A couple is eating outside at a table and he is pointing at something.
The man is pointing at a purse snatcher.
A person who is outside pointing is not necessarily pointing at a purse snatcher.
man pointing at something doesn't imply that man is pointing at a purse snatcher.
A couple need not have a man in it, it could be a couple of women or men.  Also, there are many things to be pointed at besides a purse snatcher.