Assuming Jesus of Nazareth really existed (and I have no problem with the notion that he did), there’s still no record of what he looked like, or what his mom looked like. Maybe he had a beard and long hair, maybe not. Maybe his mom went around in a head shawl, maybe she didn’t.
But why is it that whenever someone looks at a tree stump or a piece of toast or a pattern of light on the side of the building that looks like a guy with long hair and a beard, they think it’s an image of Jesus rather than, say, John Entwistle? Why does every image of a woman in a scarf or shawl remind people of Mary, rather than Benazir Bhutto?
There have been guys with beards and women with scarves throughout pretty much all of modern (or semi-modern) human history. And there’s no record, oral or written, that says either Jesus or Mary looked the way they’ve traditionally been rendered by European artists.
Sure, an all-knowing and all-powerful God might choose to take into account a particular culture’s iconography, and make His miracles conform to those traditional images. But wouldn’t an all-knowing and all-powerful God have created an iconography that’s a little bit less generic? Maybe a distinctive facial scar, or chin dimple, or harelip or something to make an actual image of Jesus next to Mary somehow distinguishable from an image that could just be from a sidewalk in Cairo or Riyadh (or New York, for that matter)?
And BTW, am I the only one who thinks there are lots of Christians who will fall down and worship an image of a woman in a headscarf if it appears on a piece of toast, but who make a wide path around a real, actual woman who’s dressed that way? Especially if she looks like she’s Middle Eastern — just like Mary was?
(Atheist melon pic from Mitchell and Webb sketch via Buzzfeed)
Atheist Etiquette 
