I don't think, there is much you can do in Photoshop.

It does not look like the figure is floating above the couch, the figure is floating above the couch.
The moment you look at the image, you notice the angles from feet to knees and from hand to elbow.
Both should form a straight line, parallel to the couch.

My suggestion would be to go back to Poser, lower the figure until knee and elbow touch the couch,
adjust bend on the forearm until the hand is on the couch, use thigh or buttock twist to
get the foot to touch the couch.

Martin

Yesterday's the past, tomorrow's the future, but today is a gift. That's why it's called the present.