Hm.
My initial thought was "subject too small in the frame, subject dead center, landscape when portrait would probably work better"... but...
The dead-centering suggests stagnance, which this is... though, I only knew that because of your story about it. I wish you hadn't posted that, because it colors our interpretation.
The wider view makes the child small, which they are... and that ties in somewhat with the facial expression (and, again, the story... ugh)
I dunno. It's a cute moment. I think I would have moved the lens to the right, tilted it EVER so slightly to the left. That would imply forward motion, but resistance against progress at the same time, which might have given you the conflict you were looking for. It also would have shown the expanse of how far the child COULD go if they jumped off (keeping it zoomed out so the expanse seemed greater).
I think that would have worked better.