Hi, Lovee! And welcome to the forum!
Your photos aren't showing up for me either, so you might want to edit your post so we can see them.
This question pops up a lot on the forum, and there's no hard and fast rule.
Factors to consider are 1.) what disicipline you ride or compete in 2.) the pony's overall conformation, sturdiness and weight-carrying ability 3.) your weight, build and riding ability.
It's not strictly a pony's height to your height kind of thing. Questions to ask yourself are - Do you feel you can get and keep your leg on the pony and that his barrel takes up your leg or do feel like there's nothing under your leg when you ride? Do you feel balanced when you jump or do you feel like you're way forward on the pony's neck?