The line you will not type
Some sentences never go in the chat as words. The picture is how they arrive.
The chat will not hold it
Come home. I miss you. You were right. I am proud of you. Sorry. Typed plain, those lines sound like a parent or a speech. So they do not get typed, and the person never hears them.
A picture can carry the line because it looks like a joke. You pick the one that is the situation. The feeling rides underneath. They answer the joke. Both of you know what it was.
Do not explain it after
"This is actually me saying..." kills the cover. If you need the explanation, you sent the wrong picture, or you were not ready to say it. Let the picture be the whole message.
The private chat is the right room. The group turns the feeling into content. One person can take it. A group has to react to it, and then it is no longer yours.