I've never seen that sort of horizontal logo before. Google's "publisher" authorship (rel=author, but for companies/organizations) can result in a logo image showing up to the left of a SERP listing (much like the author image), so it may be related to Google's ever-changing use of authorship & semantic markup.
Maybe Google authur publisher but they use small standard picture and this pic is large then standard.
Hmm... I haven't seen that on any of my listings yet. Pretty interesting. I'm already not a fan, last thing I want to have to do is scan through tons of images while I'm trying to read text about the listings.
Though black hatters have spewed so much Rich Snippets spam that Google is now ignoring most of it except from "trusted sources" which means that Goliath trumps David again.