In 2012 the Twitter timeline did not show photos. The definition of what makes a Tweet started to change in 2013 when we introduced native images. Sara Mauscopf (product manager) and I formed the Photos team and began looking at ways to improve the photo posting and viewing experience.
Photo filters and editing
I designed an improved set of photo filters and editing features for the composer. The project was shipped in early 2015.
Multi photo Tweets
As part of the original photo strategy I proposed expanding the number of photos that could be posted to Twitter. To keep the timeline dense and the essence of the Tweet brief we decided on 4 photos.
Photo formats and grids
In addition to helping people post nicer photos we needed to make sure to keep the timeline dense enough so that catching up is quick. For that I developed a set of rules for photo ratios in the timeline for mobile and web.