Peter, Mary and John

Here's a detail. The plan is to make Mary standing between Peter and John – two contrasting personalities. There's Peter who is all nerves and then John the quiet and graceful apostle. Peter already has his next question on the tip of his tongue... he means well but his own impatience is a distraction to himself. (Remember, this is just my opinion) Mary is comforting the both of them and reassuring them that her son's plan is for the good of all and that there's no need to fear the future. "Fisher's of men are what you have become!" could she have said something to that effect? And, John looks to Mary like a son does to his mother.