There's a shortcut to understanding Steven Wiltshire: follow him to lunch.
Every Wednesday and Friday, at the exact same time, the artist visits the same London sandwich shop and orders the same baked potato with tuna, corn and "a bit of cheese".
Neither his routine visit nor his routine order surprise anybody in the shop, reports CBS News correspondent Mark Phillips.
Like actors in a play, everybody knows their part, including the shop worker who gives Steven a kiss on the cheek with his sandwich.
"He loves a kiss, every day he comes here!"
It is very common for people with autism, like Steven, to apply a rigid order to their lives - to, perhaps, take refuge in routine.
"He has his favorite, Corn Flakes, and he has to have it at a certain time," explains his sister Annette, who is also the artist's manager. "His lunch is at a certain time."
"He's no different from anyone else in my opinion," says Annette.
"With autism, because it's not like Down's syndrome where you can actually see, perhaps, a more visible disability, Steven, he looks like everyone else. It's only when you speak to him and the conversations are a bit more complex, you can see that signs that are there."
Another way to understand Steven is to look through his sketchbook. His interests are all there; the buildings, the cars... the food - even a chicken sandwich. "Yeah, I copied that from the TV screen," explains Steven.
"Why did you like it?" Phillips asks the young artist.
"Because it's interesting, because I used to like chicken. I am obsessive with chicken."
Steven often describes his interests as obsessions. Lately there's a new one.
"I'm obsessed with women," Steven confesses - in an artistic sense. His sketch book reflects the focus on a new subject matter.
Stephen may be autistic, but his family has always tried to treat him as normally as possible.
"We've never made him feel like he's different to anyone else," says Annette. "I only have one brother but I wouldn't change him for anything."
By all appearances, he's a talented and happy one.
Wiltshire updated "Early Show" co-anchor Maggie Rodriquez Tuesday on the progress he's making drawing his New York cityscape:
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To learn more about Wiltshire and his work, click here to read "Portrait of an Artist as a Panorama Master."