When Facebook asks for a photo to verify account and shuts you out of your account until that verification is complete, how long does that take? And what happens if they reject your picture? Is there any way to make the whole thing go faster?
It takes 48 hours to one week or sometimes one month. There is no fixed time for it. It depends on which policy you have violated and why they have asked for photo verification. If they reject your picture, you have to contact them again. There is no other way.
There is no official way provided by Facebook to make this process go faster. You may contact Facebook for this.
Pro tip: Don't try any other way or work around, if they found anything fishy, you will be blocked permanently. Go with their process.