Some just like the way they look. I've never really found heels terribly attractive honestly. They just seem impractical which is a little off putting to me. Now that said, I do see the appeal when worn by a sub. They serve to sexualize her, especially if they're locked on or very tall. They're difficult to walk in, more so when in bondage, so they reinforce the idea of being used for the doms entertainment and also the vulnerability of the sub as their mobility is hindered.
Side note: That profile picture is ADORABLE !