Originally Posted by gerbick
I can somewhat answer this one.
The whole part of idolatry is what's going on about the picture(s) of the prophet. it's written quite a few times in the Qu'ran about how Muhammed (PBUH) - hereby "prophet" to avoid too many places I might dwell into making mistakes - forbade idolatry, as part of the principal sins - idolatry and apostasy, adultery, false witness against a brother Moslem, games of chance, the drinking of wine or other intoxicants, usury, and divination by arrows.
With that, the picture of the prophet were not forbidden; they are considered sacred. Just as pictures of Jesus were once things that could get you killed by the orthodox church - or at least banished, whipped, drawn and quartered - this is what we're dealing with now. Taking a sacred person from a religious text and painting them in a manner not befitting of their sacred position in those religious text(s). A mockery basically. The other end of the spectrum... worshipping that image, thus idolatry.
This is something I've gotten from my time while in Turkey. You didn't quite see houses with pictures of the prophets, but you saw them in the mosques... where you worshipped. And even then, it was understood that it was a reminder of who brought the word, do not worship them. Worship only God/Allah.
Now, with all of that said, I'm merely slightly answering your question. There's a few entries on how the prophet stated that his wish was not to become an icon of worship, thus idolatry.
Hope that makes sense.