Take as an example the sentence:
"The monk is skinny, his arms lean from years of cardiovascular exercise."
I've seen similar sentences and am curious about the grammar, since a similar sentence (with a comma splice) would be:
"The monk is skinny, his arms are lean from years of cardiovascular exercise."
Is this wrong (the first example - I know the comma splice is often frowned upon though controversial)? I've seen some serious authors do this so I assume it's not but I don't know how it works.