On the picture we only see the left gamepad, not the right gamepad
Anyway, the portable design of the Black Shark Gamepad is great but it's not recognized as a standard gamepad so it does'nt work directly with games with gamepad support, we have to map all the buttons with each game and this trick doesn't work as good as a gamepad with standard input buttons like Asus ROG Kunai which is WAY better for this reason
Xiaomi, have a look at the latest Kunia gamepad by ASUS for the new RoG Phone 2.
Imitate that, but have it in a way, which doesn't require the owner to use a phone case (ie Slides on like a Nintendo Switch). And make sure that, both left and right JoyCons can come off, and be put together into the same pocket, and that it fits in a Standard Denim Jean Pocket. That way you truly have something "pocketable" like a PSP Go, and not something that needs to go into a purse/backpack like the huge Nintendo Switch.
And if you do a good job, you can make the same gamepad hardware for years, and have it compatible with your notable devices (Mi, Mix, A, Redmi Note, etc).