So here’s a thing:
- she’s got her arm over her head which stretches the muscles and makes it look leaner
- her head is angled towards her shoulder which makes her neck tendons and collar bone stick out
- she’s pulling her shoulders up and curving her spine which sticks her boobs out and stretches her core, pulling her tummy in and emphasising her abs
- she’s leaning her torso forwards and sticking out her bum which lengthens her thigh muscles giving her a gap
- she’s on her tip toes which stretches her leg muscles making her legs look longer and leaner
She would look quite different if she was standing normally or relaxing, or slouching like most people tend to do.
And all that without the airbrushing that was probably done in post.
Don’t compare yourself to these images.