this was a very informal interview
I showed up wearing a suit, and the two people interviewing me were 20 somethings with rudimentary interviewing skills, one wearing a hoodie, both wearing jeans. dogs were running around in the meeting room next to ours. DONT GO INTO THIS INTERVIEW EXPECTING A STRAIGHT LACE ENVIRONMENT, you'll come off as type A, and stuffy.
know what you're walking into and get yourself in the right frame of mind for it.