Enlarge Image Sportsfile (Web Summit)

DUBLIN -- Smartphones and mobile apps, Instagram in particular, have helped set off a new explosion of photography in the past couple of years. But while a picture paints a thousand hashtags, it's important to remember the context and nuance an image can't show.

That was one of the points I discussed Tuesday with Instagram co-founder Mike Krieger and Anna Dickson, Google's photo lead and formerly of The Wall Street Journal, Huffington Post and Rolling Stone. At the annual Web Summit here, we chatted onstage about how social and mobile technology are shaping the way photography and journalism work.

Krieger co-founded Instagram in 2010 with fellow Stanford student Kevin Systrom. Bought by Facebook in 2012 for around $1 billion, the phenomenally popular photo-sharing app now has 400 million people that use its site at least once a month. Krieger said 80 million photos are shared per day.

Dickson discussed the increasing prevalence of imagery in journalism, describing how pictures were traditionally the last thing journalists thought about, but are conversely the first thing readers see. She noted too that pictures are a global language.

Dickson emphasised the importance of authenticating a picture and looking at the context to ensure that a photographer doesn't "tell a story that they don't want to tell." She gave the example of dramatic photos taken in the troubled American town of Ferguson, Missouri, and during the refugee crisis in the Mediterranean as examples of pictures that could shape a narrative. When a scene is depicted from another angle or framed another way, it could show things differently, she said.

The question of context and the story behind an image has come to the fore with the news of an "Instafamous" social-media celebrity who has revealed the unhappiness behind her carefully honed online image. Australian Essena O'Neill, now 19, began crafting her online persona at 15. She has deleted many of the Instagram posts depicting her apparently carefree, glamorous life, and has edited the captions of others to reveal the artifice behind them. That ranges from staging "candid" shots to potentially damaging her health to look good in pictures and videos. She now admits that her quest to present a "perfect life" left her feeling "lost, lonely and miserable." O'Neill has also pointed out that she was paid to feature brands in posts without making it clear to the viewer.

Krieger addressed the question of posts that have been backed by commercial interests without making it obvious to the viewer.

"I hope in the long run [the culture] is self-regulating," he said. "Accounts that tend too much towards the commercial or that feel too much like product placement, eventually people just unfollow." But he ruled out telling people "you can't do that", because "policing 100 million people is just impossible."

Krieger pointed to National Geographic as a brand that uses Instagram to tell a story by posting images with a lot of impact and then filling in context. He gave the example of a picture of a sheet of ice, with the caption chillingly explaining the amount of ice in that area has been drastically reduced.

Looking to the future, Krieger lamented that people have, from the start, thought of Instagram as "the photo company" and counters that. "We never thought of ourselves as a photo company. We thought of ourselves as a communication company that happens to use JPEGs to transfer information back and forth."

Instagram expanded into video in 2013. Last month, Instagram launched Boomerang, which creates short five-frame videos that bridge the gap between a still photo and a short video. It's similar to Apple Live Photo and HTC Zoe, which also capture subtly moving images.

What's the future of photography in this social, mobile age? "I think the 360-degree VR selfie is the next selfie," joked Krieger.