I was at a wedding on Friday & saw a gorgeous girl with a racer-back style dress. She just looked young & thin, didn't look like she under eats especially or is trying to build muscle, but I spotted slightly developed lats on her. Found out later that she is a Pilates instructor.

There is a strong focus on bringing your shoulder blades together & making your movements controlled & stable in Pilates. If you have a good instructor you can get a lot out of it.

But it was more likely the deadlifts & a general leaning out for me.