many anatomy, posture problems. The far leg and the far arm especially don't seem to be proper in shaping and length, and are not comfortable in that position. Sadly I can't offer much critique on how to fix such an issue as I identify it as one that will go away the more confident you get drawing people, so I guess, do do do do it more.
The posture is not very dynamic, it has to do with the angles of the limbs and body. If you want a general edit I could.