That posture is a sign of dementia. Specifically fronto temporal dementia.

Pretty sure it’s the lifts in his shoes. He’s worn them for years because he can’t bear to be under a certain height. They tip his slightly forwards, so he stands like the front half of a centaur.

It’s really weird, but not one of the many signs of dementia he shows, just vanity.

Nah. High heels don’t do that. If anything it causes you to lean back to offset the slope.