That honestly looks like a better design than the original N64 controller. I mean access to both the Z and the L button without having to change your grip, hell it's like it's actually functional.
That honestly doesn't look like it would be bad to use. If you're holding it close to your chest, that seems like it would have your hands in a more natural position, so it's probably ergonomically better, for some people.
I googled it.
It's a Nuby Boomerang 64, there is a trigger on each side underneath and a slot for the rumble/memory pack.
So yeah, that might actually work better for some games at least.
My older brother had one of these. I used to play a bunch of games we got in cereal boxes with it. Discs were the size of gamecube games, and completely slipped off the disc tray and he'd have to disassemble it to get them out for me. Excellent older brother behavior, until he finally forbid from putting any more shitty cap'n crunch branded video games in his computer. Lol. Controller was good though, iirc
Edit:
Upon googling for nostalgia's sake, I'm mistaken. It wasn't this one. This is specifically for N64, ours was on a pc. Super similar to this one, but I can't find the one we used.
Those cereal box games were so cheaply made they had a tendency of blowing up when spun in a high RPM disk drive. The ones we had weren't mini disks but we had one blow up on us, although we did get some RollerCoaster Tycoon games from them.