Keen Observation. She looks delicious. I didn't notice at first that she was the the only one showing a whisper of tan lines in that marvelous lineup.
Also the only one of two models sporting a tattoo.
They are all gorgeous but my eyes tend to gravitate more towards prominent tan lines like those displayed by the model fifth from the left. Especially the back end pic.
IMO framing a gorgeous butt with a tan line like that is a thing of beauty. What an invitation for some of us ass loving guys