I recently moved my 3 axolotls from plastic tubs to an aquarium. They lived separately in the tubs so this is their first experience seeing each other and their own reflections in the glass.
One of them (Blingbling a gold albino) has a "special greeting dance" it does when it approaches the others or its own reflection in the glass. It goes something like this: slow motion step forward , bob head, wiggle gills, bob head, bob body repeat.
Last night I watched it do this to its self in the glass several times... cracked me up every time.