Great that they are taking steps to help educate contributors on SEO. Personally, I feel a proper SEO test should involve a bit more than a single title and short description tweak. Those 2 actions alone won't make much of a weight change in the Google algorithm .. unless they plan on moving to 500-800 word image descriptions.  .. Nonetheless, education is always good.

@ShadySue - Yeah, I'm thinking that focusing on good keyword practices would be a higher priority. That would make buyers very happy.