Do you need another breaking news bulletin to inform you that flip flops are not appropriate attire for WORK? Unless you work at the beach or perhaps the community pool. And since I happen to work in the same building as you, I'm almost certain you don't work at the beach (although I have never seen what's on the third floor...also, in case you were wondering, since we are not allowed to swim in the fountain, it does not constitute a swimming pool). Seriously, people. It doesn't really matter how much you overpaid for your flip flops or how luxurious the material is from which they were crafted. They are still flip-flops. The end.
P.S. While I'm doling out work-related fashion advice, might I recommend that you introduce your skirt to your knees. Or at least the bottom of your underwear.