First of all Myboypuck has excellent critiques, however she wishes to demure.
Once she said that about hte back and shoulders , I realized that that was what I see , too.
The pictures are , sadly,, not so good to critique from. YOu are actually a tidy rider on a cute horse. I get the feeling that you are close to where you want to be. The over arching in the back , rolling too far forward on the pelvis , is part and parcel with piano hands. You give away forward the centererd strength that comes form keeping your elbows attached to your ribcage and using the single most powerful muscle group, your abs, to ride with.
I think if you ride really thinking about having your elbows in this will naturally casue the puppy dog hands to go away. And if you think of really bringing your hands and core together with each rise of the posting trot, this will help to keep you more uprgith, and help develop steady hands and a strong center.
Try really visualizing that you ride from you belly button area, and that is where your heart and brain reside. Let your core lead you.
Good leg position and like I said, overall tidy rider and very cute horse.