Not sure if Puzzling is the right place for this, but I couldn't find anywhere else to ask.
I've been seeing this image circulating around a few Discord servers:
When converted to mp3, you get the Super Mario Bros. Super Show end theme.
I remember image files holding .rar(?) files from the SiIvaGunner ARG, but that and this are the only instances of this I can find.
How exactly does this work, and how does one go about doing it?