Think he's mostly frustrated with himself, and consequently departing after two big misses. He certainly hasn't lacked for effort in this one, just end product.
I like to think he's just disappointed by his missed chances. Now that Tadic has scored almost as soon getting on the pitch, Mane can't really complain too much.
Would I be right in suggesting that Ronald has got this tactically spot on? And an excellent substitution too?
Ah yes, my bad. A little twist of luck and look what happens. We're so quick to criticise when we believe things are wrong, it's only right to praise when it goes right.