I like the spread of subtle pastel colors and the sense of age in the 'face'. Technically, the only nit I have is the branch at the lower left appears to be out of focis; but that just might be a trick of light, since I'm looking at a low-res image.
Artistically, I tink you could darken the area of the left 'eye' to make the 'face' instantly recognisable. Perhaps the 'mouth', also, then lighten some of the highlights for a bit more 'snap'.
Just personal opinion, of course.
I didn't vote in this challenge; I would have rated this higher than the average you received. It's a clever piece of work.
Very trick photo to see the face in but well done. It looks like one of those new style art works where you gotta stare at it to see the pictures even tho they aren't realy there and everybody that does see them lies. :D <9>