I can think of a couple of reasons why:
E: What's with the bonks? It's obviously the angle she's holding the cards. Ideally she should be holding up the cards at eye level so she isn't craning her neck. The table is also a bit too high, so it would naturally make her roll her shoulders, leading to a slight hunch when she puts her arms over it. As much as possible, the table should be level to her arms, with her lower arms forming a 90 degree angle relative to the desk.