Can you use the word "play" even though he's merely picking an emoji and not playing a game?
Native speaker’s answer
Rebecca
In this case, yes! "Play" here means movement or action. They are saying he's not sure how he wants to approach his next move. This term is used in other sports and games when a player's move is called a "play". Ex: That was a good play in the second half of the match by Thomas with the ball! Ex: Jenny is thinking hard about her next play. This move could cost her the gold medal in the chess tournament.