Probably cuz it's a photo.

are cool, they work just fine, i like the tile a lot. i think it's cool that you like to scan stuff too. even cooler that you scanned your nose haha. :o)

as far as the "don't use photos - we wanna see what you can draw" - business goes... i don't think it's a case where your tile will be deleted on a mainquilt for using a picture, [it might on an invite quilt, i don't know].
but if playing by the rules, or how people score your work matters at all to you, then i guess it matters.

also, i would not presume to tell anyone how to be creative, or what does or does not constitute art. i only mentioned it to be helpful... it's what i was told when i started [i got spanked with some real low scores for not "drawing"].
in the end it's really up to you ;o)

peace