You seem to think that those options are exclusive when in fact gif memes are a blatant example of how they aren't.
The original creator of (say) a video expresses something, a remixer expresses something when they cut it into a gif, and you're expressing something when you send someone the gif in a conversation. The thing that's expressed is almost necessarily different, and each step involves creative choices.
The original creator of (say) a video expresses something, a remixer expresses something when they cut it into a gif, and you're expressing something when you send someone the gif in a conversation. The thing that's expressed is almost necessarily different, and each step involves creative choices.