The theory I've read is that those Friend AI ads have so much whitespace because they were hoping to get some angry graffiti happening that would draw the eye. Which, if true, is a 3d chess move based on the "all PR is good PR" approach.

If I recall correctly, people were assuming that Friend AI didn't bother waiting for people to vandalize it, either—ie, they gave their ads a lot of white space and then also scribbled in the angry graffiti after the ads were posted.