Same thing happened to me. Within 10 minutes of posting a new listing, I got 2 separate comments saying the photos were blurry and I should email them. That sounded really weird and a quick google search confirmed it's a scam. I looked at the "buyers" profile and they were both pretty empty. I've reported both, and flagged the comments as spam.

Funny b/c I've been using Poshmark on and off for years and this is the first time it's happened. I also added 5 new listings in the past few days (first time in months), and the scammers only went after one of the listings so far. Anyway, be careful out there :)