The command, if it's ran in the bots DM's, will search through the official Pepe Emoji Servers, and not the last server you visited/interacted with.
The search is a loose match, meaning that the letters in the keyword must in the correct order for the emoji to be a match, but the keyword you enter can be located anywhere in the emoji name itself. The search will only work with Alphanumeric characters (Letters and numbers).