No, not actual censorship of, say, nudity (Ravelry guidelines require it to some extent, though Mr. Naked Hat Gentleman seems to have figured out the system.)
I'm talking about censorship of your FACE.
Why, why, why would you do this to your picture?? The focal point of your pattern photo should be your beautiful knits. As soon as you add a big, bold, geometric shape, you've shifted the focus, and to something ugly and brash and unpleasant, no less. Human beings naturally look for faces wherever they go- that's why we see a man in the moon and attribute facial expressions to things like houses and cars. When you intentionally take a face away from where it should be, it becomes jarring and unnerving. That's why tv-heads are so creepy (which is exactly what the artists want them to be, because, societal statement, blah blah, conceptual, meaning, blah, feelings, etc.)
On top of completely ruining the aesthetics and kind of creeping people out, censoring the face says one of the following:
A) This is the only picture and the model was making a stupid face but I'm too lazy to reshoot it. (Solution: RESHOOT IT. And take a tontonTON of photos whenever you're shooting something so it will never happen again.)
B) I modeled this, and my self-esteem is so low that I can't bear to let people see photographs of me. (Solution: D-: That's really sad and you should work on that, but in the meantime, get another model, position yourself so your face isn't visible in the photo, or crop it out if you're not modeling a hat. Just don't *censor* it.)
C) I don't really understand how internet stranger danger works, and still believe that putting a photograph of myself online will result in an instant murder-stalker tracking me down.
(Solution: That's probably not going to happen. Don't go posting your address, phone number, and SSN or anything, but you're more likely to meet a nice potential murder-stalker at the grocery store than through a photograph you posted on Ravelry.)
This says all of the above plus "I am probably using MS Paint" and "I somehow have no awareness of how creepy this is." It's really, really, really creepy. REALLY CREEPY. OMG.
So... come on, ladies and dudes. REVEAL YOURSELVES!
^^^ also creepy