Written by Rebecca Wright, CNN

During the final days of Hong Kong's Umbrella Movement in 2014, several banners and posters emblazoned with "we'll be back" were left behind on Harcourt Road, a major thoroughfare of the city occupied by pro-democracy protesters for 10 weeks.

Those banners carried a message of defiance, and also of hope, that despite months of demonstrations resulting in little political action, protesters would once again unite against the government.

And true to their word, they did return.

Pro-democracy protesters sleep next to a sign reading "we'll be back" on a blocked road in the Admiralty district of Hong Kong on December 11, 2014. Credit: Alex Ogle/AFP/Getty Images

The past two months have seen an unprecedented social movement in the city. Hundreds of thousands have taken part in mass rallies sparked by opposition to a bill that would allow residents to be extradited to China.

Though the extradition bill has been shelved, demonstrations have continued, with protesters widening their demands to include calls for greater democracy and police accountability.

In recent weeks demonstrations have become increasingly violent, as protesters engage in street battles with riot police amid clouds of tear gas. More than 500 people have been arrested in connection to the protest movement since early June.

Underpinning the movement, which is now entering into its tenth weekend, is the ongoing creation and mass dissemination of protest art that informs, inspires and, at times, offers light relief.

Posters such as this one list out protesters' demands. Credit: Telegram

Posters are designed to encourage unity among protesters. On the top right, petals of the bauhinia flower -- which features on the city's ensign -- are wilted, with "the last of us" nodding to what some Hong Kong people see as the erosion of their local identity. The phrases "liberate Hong Kong and "revolution of our times" are written in Chinese. Credit: Telegram

In Hong Kong, political art has taken on a distinct style, from design to distribution. Banners are not just plastered onto main roads -- they are sent directly to residents via Bluetooth and Wi-Fi almost immediately after they are created.

The graphics serve multiple purposes; some advertise upcoming protest marches, others contain subversive criticism of the authorities and many encourage unity and stamina.

A key theme of protesters' posters is the ability to "be water," a phrase inspired by martial arts icon Bruce Lee that encourages fluidity and adaptability to any situation. This is in stark contrast to the 2014 protests, which remained in one area of the city as protesters set up camp against the authorities.

Protesters often use the phrase "be water." This poster was distributed on Telegram by an unknown artist. Credit: Telegram

Referencing the design of Chinese paper calendars, this poster is urging Hong Kong people to strike. The widespread strikes on August 5, 2019, brought Hong Kong to a standstill. 2,300 aviation workers joined the strike, according to the Hong Kong Confederation of Trade Unions, leading to 224 canceled flights. Credit: Telegram

The new messaging reflects changing tactics and lessons learned. After protesters stormed and vandalized Hong Kong's Legislative Council building on July 1, CNN asked one young participant what she planned to do next. She simply replied, "We don't know. We will follow the people. We want to be water."

This ability to "be water" is aided by evolving technology, which enables information to be widely circulated with speed and efficiency. It also capitalizes on the digitally-connected nature of the city, with minute-by-minute updates being communicated through encrypted messaging app Telegram, as well as other social networks. The AirDrop file-sharing function on Apple's iOS has also become a popular way to anonymously distribute protest posters in busy public places.

Kacey Wong, a visual artist and activist from Hong Kong, said the speed with which posters are created is also a reflection of the city's connectivity.

"A lot of Hong Kong kids have design training and are highly skilled with computers. For example, Photoshop and other design tools -- they learn in grade school," Wong said in a phone interview.

"Publishing in Hong Kong is also very quick and cheap; we send the file in the morning and you get it in the afternoon."

This poster is a play on "mind the gap" signs in the subway. It's a reference to a mob attack that injured 45 people in July. Men in white t-shirts and poles attacked anti-extradition bill demonstrations at a metro station in Yuen Long. Credit: Telegram

A Star Wars-inspired poster informs protesters that a demonstration will be held in the Sham Shui Po district of Hong Kong on August 11. Credit: Telegram

Selecting designs often takes place on the LIHKG forum, Hong Kong's equivalent to Reddit, where users vote on the best posters for wider distribution. This use of crowdsourcing fits with the egalitarian ethos of the demonstrations, which are leaderless in nature, while helping individuals avoid future punishment (after the 2014 Occupy protest, a number of student leaders were jailed for their roles).

"I think it reflects and emphasizes that it is 'by the people, for the people,' and there is no true leader in this movement," a 22-year-old protester, who asked to be identified as Sarah to hide her identity for security reasons, said in a phone interview.

Social media is not the only distribution platform. There are also physical "Lennon walls" springing up all over the city. The colorful mosaics, comprised of Post-It Notes, are named after a 1980s Prague mural that was covered in Beatles-inspired lyrics in protest against Czechoslovakia's communist government.

A makeshift "Lennon Wall" appears at Sai Wan Ho district on July 20, 2019 in Hong Kong. Thousands of handwritten messages are written onto Post-It Notes. Credit: Anthony Kwan/Getty Images AsiaPac/Getty Images

The Post-It Notes on the Hong Kong versions, popularized during the 2014 Occupy movement, contain inspirational and supportive messages for the protests.

"When we understand the wall, we usually think about our Instagram or Facebook, but what we have seen since five years ago is interchangeable -- the physical wall in the Occupy zones," Wong said. "The merging of the two walls, the social media walls and physical walls."

The Lennon walls also fit the protesters' "be water" strategy, flowing to all parts of the city and seen by all layers of society.

"Our older generation, aged over 50, are not highly connected, and we also have some young but totally disengaged (people)," Wong said. "So the physical walls spreading around the community are a very effective tool to advocate the desire for democracy and freedom among the population."

The Lennon walls also create an immersive experience, which allow people to feel connected to others, Wong said.

"In a cellphone or desktop, we are usually reading one image at a time, as our monitor is limited. But when you experience something like the Lennon wall, it is a whole tunnel, a physical space which envelops you," Wong said. "Suddenly you see all these voices, they are like the inner voice of yourself written down on the wall. You will not feel lonely anymore.

"It is very powerful as an experience, psychologically, and it is very empowering," he added. "As an art form and as a platform for the voice of the individual, it brings the solidarity of the people together."

Ahead of Chief Executive Carrie Lam speaking to press in August, protesters created a Bingo card guessing what she might say. Credit: Telegram

A poster reminds protesters what to bring to demonstrations, and how to protect themselves from tear gas. Credit: Telegram

When it comes to posters, designers take influence from a range of artistic styles. Japanese anime has been used to depict heroic characters defending themselves from tear gas using umbrellas. Superhero symbolism is also popular, particularly the shield used by Captain America.

Dan Garrett, a political scientist and author of the book "Counter-hegemonic Resistance in China's Hong Kong: Visualizing Protest in the City," said that dystopic, anti-authoritarian genres resonate with the protesters.

A protester holds up an anime-inspired poster. Credit: Rebecca Wright

This poster encourages unity among Hong Kong people. It says "together let's support until the end." At the front of the rope is a man in a yellow raincoat. This symbolizes the first suicide associated with the Hong Kong protests. A young man fell to his death after unfurling a protest banner near government headquarters in June. Credit: Telegram

"(Genres depicting) heroes and heroines defeating evil totalitarian regimes and rulers, despite insurmountable odds, appear to be particularly motivating among the younger generation of Hong Kongers on the frontline of the resistance movement," he said.

Hollywood movie-style posters have also been used, with dramatic imagery of protesters and riot police enveloped in clouds of tear gas, accompanied by messages of revolution and heroism such as, "We rise as one, we fight as one." Others are more like album covers for rock bands, like one titled, "The last of us" -- an effort to inspire protesters who are willing to carry on the fight.

An example of a Hollywood-style poster. Credit: Telegram

Garrett said inspiration is also being drawn from historical events.

"There are visual references to contemporary and past social movements such as the civil rights movement in the United States, the French Revolution, the South Korean democracy and labor movement, and the Euromaidan in Ukraine among others," he said.

Some of the poster art is reminiscent of wartime military recruitment campaigns, with bold imagery and messages such as "We need you" and "Fall in."

Unity is also a key theme throughout the posters.

Sarah said her favorite ones are those depicting society pulling together, including one showing people in a tug of war against a giant fist.

Hong Kong's unique sense of humor, which is simultaneously gentle and subversive, often uses creative plays on words or images, and is apparent in many of the protest artworks.

When an application to march in the outer town of Yuen Long on July 27 was denied by the authorities, who cited safety reasons, protesters instead announced that they would hold a "memorial service" for former Chinese Premier Li Peng.

Li, who had died a few days earlier, was lauded in Chinese state media as an "outstanding proletarian revolutionary, statesman and leader of the Party and the state." To critics, he was known as the "Butcher of Beijing" for backing the use of force to quell the protests in Tiananmen Square in 1989.

The Yuen Long protest went ahead despite police objections and ended with tear gas and rubber bullets being fired at demonstrators.

A poster depicts a man's scars, made after a photo of a cook, caught in the Yuen Long metro station attack was circulated online. The red welts in this are arranged in the characters "harmony." Credit: Telegram

Messages like these offer light relief. Credit: Rebecca Wright

"I think the humor appeals because the situation has made so many people angry," Sarah said. "And much of what has been done or said by the government and some police officials has been seen as a joke by the protesters."

Creative plays on existing designs include reworking the subway posters to say, "Mind the Thug," and changing the national emblem of communist China to include CCTV cameras, tanks and handcuffs. A Hong Kong-style wedding invitation was also sent out to celebrate the "marriage" of Hong Kong and freedom.

This poster breaks down the different types of people seen at the protests. Credit: Telegram

This poster informs people that a protest will be held on August 10 at the Wong Tai Sin district. Wong Tai Sin is famous for its temple, a large traditional complex devoted to a Taoist deity of the same name.

And at a peaceful protest at the city's airport on July 26, some protesters held up posters saying, "Hong Kong is down for maintenance. We are trying our best to get it back up."

"The humor is very effective," Wong said. "It is an uncensored platform, (so) they don't have to worry about bearing any consequences and, in that sense, it is an interesting way to read the psyche of the people."

It's also a way for the people to express themselves during a time of upheaval in the city, Wong said.

"In Hong Kong, we still have some freedom of speech left, although it is being tied up quickly," he said.

"I don't think the poster phenomenon is caused by a crackdown on freedom of speech, it is more of a need for a personal platform for their voices to be heard."