I presume it was the autofocus on your camera that made her ear sharp but not her nose and maybe even the camera that selected a big aperture for the lowlight but that gave you shallow depth of field. The framing of the shot, all yours, is great, it evokes that same moment for all us dog owners and pet lovers. It has a touch of doggy melancholy, she might be tired but she really doesn't want to leave the forest yet. :) Nice shot.
Mikel.