The light bulb effect

So... I can’t remember where I’ve seen this before, but a friend sent me this picture and said he found it in his music department. He and his friends were puzzled as to what it’s true purpose is. I remember it being a joke and used to confuse people, but I can’t help but wonder if there’s something real about it. Anyone have any answers to this? I’m sure playing the electric lightbulb is quite prestigious.