You look pretty good in the first pic. You let the horse do the jumping part. You're just enough out of the saddle, lower leg secure, back flat. (maybe a smidge arched)
Second pic looks like you're trying to do more than you need for a cross rail. You're jumping ahead and your lower leg has slipped back. Maybe practice some grids that combine both fence heights on either a bounce or a two stride to work on keeping steady over the fences regardless of the height you're jumping.