Lifting your bum up via weight training

I know working your hamstrings makes them more defined and shapely, but how does toning your hamstrings lift your butt up and do you know what exercises are most effective. It confuses me because some ig fitness models and stuff have defined hamstrings but theyre butt doesn't appear very lifted/ high up.
any answers would be appreciated thanks :)

by bitMEL via Bodybuilding.com Forums - Female Bodybuilding