First:The guy is rather handsome.
Second: It is difficult to interpret the guy's expression. He doesn't look sad, more bored. Or maybe he is trying to remember what he should buy at the grocerystore.
Third: It is a mismatch between the guy's casual clothes and his drink. If it is an orange juice it is a match, but a drink would demand better clothing.
Fourth: IF he drinks OJ, then he is not really looking for a date, and the drink doesn't match the girls'
Fifth: It looks like a setup. Not a real place where people meet. It is just two tables and no obvious sign this is a place where boy meets girl.