It's nice to give people's comments likes.
Tom sees a Facebook comment his friend made that congratulates him on a sports win.
Tom wants to interact with his friend's Facebook comment.
"Tom gives the comment a ""like"" emoji because he finds it a nice comment."
"Tom gives the comment a, ""sad face"", emoji as a prank."
Tom and his friend discuss the sports game in a positive manner in subsequent comments.
Tom's friend is confused and Tom tries to explain himself later.