Interesting. Sounds like it does share some ideas, but with a different goal. This blurb says it was trying to get people to complete for a spot on a leaderboard, whereas A/B testing is about helping people make every-day decisions.
That's closer! But the devil is in the details. They have you looking at one image, reading the question, and rating up/down and even commenting. In the image, they have a full body shot, with simply "Does this work?" Does what work? The glasses, the shoes, the dress?
This takes a lot more effort than simply tapping one of two photos without reading anything. A/B responses can be given in less than a second. It's all snap judgements -- no reading is necessary.
It received venture capital, but died a painful death.
http://www.crunchbase.com/organization/fashism