Why’s it even called a Gravity Rod, anyway?

It’s got nothing to do with gravity, as we can see from the above. Indeed, it should be a star rod, no (and eventually, it gets called a “cosmic rod”).
You can all guess how it works, right?

It’s a stellar-powered-vibrating-gravity-phallus that works… magnetically.
It’s almost like the creator of Starman traveled forward in time, read this site, and created the perfect item of mockery.