Is it normal for girls to post swimsuit photos on their friends circle?

This is very normal. Moments is for recording your life. For this girl who posted swimsuit photos in Moments, it was just a normal record of how she looked in a swimsuit this time and what she looked like. It's like playing for the first time. Furthermore, there is nothing special about taking photos of swimsuits these days. It’s no matter what era you are in. You can wear swimsuits to play, so taking photos is completely normal.