As of October 29, 2013, Twitter altered its timeline to display expanded views of images and Vine videos in tweets, for both organic and promoted activity.

This is similar to what Facebook has been doing for some time now. It could be viewed as the social network’s answer to banner ads, involving increased graphical presence yet arguably remaining true to facilitating engaging content rather than straightforward advertising.

Much as Facebook often recommends leveraging photo or video page post ads as the most effective format—due to the larger real estate they occupy in newsfeed as well as the eye-catching nature of the visuals—we are likely to see increased use of images in tweets, particularly for the promoted variety.