A man is painting a picture outside behind a crowd.
A man is recreating the Mona Lisa outside in front of a crowd.
Painting outside in front of a crowd doesn't mean a painter is recreating the Mona Lisa.
There are other things the man can be painting besides the Mona Lisa
The man could have been painting anything other than recreating the Mona Lisa. Also, you cannot be in front of a crowd if you are behind it.