Man in plaid shirt sings into microphone while playing an acoustic guitar.
A man is at a concert playing for a large crowd.
Singing into microphone while playing an acoustic guitar, does not necessarily mean the man is playing a concert.  Therefore it also does not necessarily mean he is playing for a large crowd.
Not all performers perform for a concert.
It's possible to play guitar and sing into a microphone alone, without playing a concert for a large crowd.