There's something twisted about this scarecrow. Perhaps it's the limp flower and the clenched fist or the way the faceless head still shows a face in the folds (slanted eyes and a frown). Eerie.
Something about this shot just grabs me. It has a sweet simplicity in subject matter, composition, and choice of black/white that is overall quite stunning. Good luck in the challenge!
I'm not sure where the mask is in this photo compared to the blank face. However it is a nice photo, sharp, subject is very noticeable. The shirt is a little hard to notice against the trees. If you use Photoshop and haven't you should try playing around with Image->Adjustments->Black and White... it allows you to shift the colors before converting to black and white and can increase the contrast between two colors.
Do you mean "Guardian"? This looks like a miniature holding a dandylion in some grass, but overlooking the surroundings it really looks like a real person.
Ah - a member of the AGC (Agrophobics Gardening Club), popping the mask on helps them feel they are still indoors and they can get on with the weeding - just like this chap here :- )