I've seen this a few times now in posts, but what's with the small 3b sizing OOP?

I'm going 3x PFR's open IP and ~4x OOP. So I'd probably go around $2.75-$3 here. It's not like we generally WANT to get called that often and have to play a big pot OOP.

Case in point, this hand.

I think calling here and c/f river seems fine with no draws on the flop.