A small Twitter update is sending a strong message regarding how the company expects users to tweet moving forward.

A change to Twitter's iOS app on Monday automatically surfaces the user's photo gallery instead of a keyboard when the user begins to compose a tweet. If a user does not want to include a photo, she can tap on the blank text box and the photo gallery will be replaced with the traditional keyboard.

This change is now the default for users that open a new tweet within the mobile app; users cannot change the default back to a keyboard at this time, according to a Twitter spokesperson.

Sharing photos just got easier on your iPhone - now it takes just one tap to select from your photo gallery. pic.twitter.com/Wj0m2CIrk6 — Twitter Mobile (@twittermobile) December 23, 2013

The change is a small one, but continues to prove the importance of photos to the social media company. With the success of apps that place a strong focus on photos, like Snapchat and Instagram, Twitter's subtle change is a reminder that the company wants users to continue sharing photos, first and foremost.

Left: Twitter's old default was a keyboard. Right: Twitter's new default is the phone's picture gallery.

Monday's update is yet another new photo-related feature that Twitter has rolled out over the past 12 months. Since last December, Twitter has added filters, enabled photo sharing in direct messages and changed the in-feed experience to show larger previews of photos.

Some of Twitter's changes appear to mimic other photo-sharing apps. Filters, for example, were popularized by Instagram before Facebook purchased the app in 2012 for $1 billion. Later that year, Twitter added new photo filters to its app, too.

Earlier this month, Twitter updated its Direct Message feature just two days before Instagram announced Instagram Direct. Twitter's update enabled users to privately send photos as messages, essentially the same functionality unveiled by Instagram.

Photos are very important to Twitter, and this trend will continue into 2014. Monday's change simply reinforces the company's belief that users want to tweet images.

The update is only available for iOS at this time. There is no timetable for its availability on Android yet.

Image: Christopher Furlong/Getty Images