Upon pressing the button "Toggle character stats" the player portrait gets smaller, and of you press that same button again the portrait gets bigger, just as it should.

Although, if you press the "Toggle character stats" button and have it open when you close the character pane the portrait does not reset in size when re-opening it. Also, the stats does disappear so the two do not match.

Perhaps a tickbox somewhere, where you can have the character stats reset upon closing or staying.