Needs a few more lights on it.
It IS just a prototype.
Assuming this thing actually "worked" (turned out more power than it consumed), it would still be nothing like a "warp core."
Basic principle is the same: reactants introduced at opposite ends, constricted magnetically and forced together in the reaction chamber which then extracts power from the reaction. The only two differences are
1) antimatter is not used (because there isn't enough antimatter on Earth to use it as a fuel source) and
2) Dilithium crystals are not used, because they are not a real thing.
Basically it's as much a warp core as a cell phone is a communicator.
A fully functioning CT reactor would also not be a "warp core" any more than a flashlight is practically a phaser.
To be fair, it's closer to comparing this thing
to a starship phaser. At least to the extent that anything on Star Trek will EVER come to exist in the real world, we could mark this down as another confirmed Trek prediction.