What does the push notification with a white chat box with a heart inside mean?

[AC Question]

I noticed a status notification on the top status bar of my bf's Galaxy. I am curious as to what it is. It is a white chat box with a heart inside. The heart has no color, and the white chat box's bottom arrow tip is pointing straight down in the middle. It looks like an Instagram like message notification, but it's not orange and there is no number next to the heart. Does anyone know what app uses that kind of notification?