The original meme: https://knowyourmeme.com/memes/giant-thumb-guy
Usually the person on the left is saying something negative that the group enjoys. Then one person of the group gives them a dismissive thumbs up and continues their convo. In OP the joke is that the thumbs up kind of looks like a cello, instead of the normal meme layout instead the guy is simply asking for a cello and the group gives him one.