The video-sharing site is starting to put out its own custom emotes. The platform previously allowed individual streamers to offer their own reactions and Emotes, but they are no longer allowed. There will be more over the course of time.
When you open the emoji picker, you will see a list of YouTube emotes below the custom ones. If you type ":cat-orange-whistling:", it will automatically fill a comment with an orange cat whistling.
There isn't a pogchamp emote, but there isn't a default for the LUL twitch emote. GG and buffering games are over.
We are starting with emotes created for gaming but are working on bringing even more themes of emotes in the future.
With this creator focus we will likely see more Emotes from independent artists in the future.