Ttiotsw says:
>>Thus whereas the Jesus article has 90% images of Jesus, the Muhammad article has only 30% images of which 20% are contentious and would have been edit-warred over. It would seem to be an unrepresentative view to simply remove the last few images from the article.

My answer: 
Jusus article has 100% images of Jesus which are accepted/used/associated about Jesus in 90% of Christianians.

Muhammad article 100% images of Muhammad which are accepted/used/associated about Muhammad in 0.1% of Muslims as well as nonmuslims in all the history. 

There is not even a single mosque having the image of Muhammad hanged and represented, which proves that the image in wikipedia article is purely a POV for few people who argue about the image that it is related to some 'unknown' painter and was used in a short span of history.

Use of the image having no source and no creator, is the violation of wikipedia images policy and not my personal opinion.

If there is an image which represents and is associated to Muhammad in mainstream Muslims/nonMuslims then use it. If there is no such image then it does NOT imply that you put some non-representing image or you put some image which is not associated to Muhammad by Mainstream Muslims/nonmuslims but by very few people in a short span of history.