With PlayStation2s and Wii's the Motherboards can be trimmed down almost to 70% Factory Spec, and they are low powered consoles, they don't require a high amount of power delivery, besides a 8V battery pack, specially the PS2 Slim, i don't know how much the Wii needs, but i bet its the same.
Now with the PlayStation3 its a different story, the motherboard cannot be trimmed down as far as i am aware, active cooling is needed, or you'll risk burning the chips themselfs, even at the latest Super Slim revision, not to mention the power supply needed its almost 160W for the last revision, that is the Super Slim, no Battery Pack will be able to feed that Desktop Grade GPU and the CELL.
Unless you have technical knowledge and board schematics, and a common sense on how the machine works, then it might be possible, but realistically speaking, a Portable PlayStation3 its out of the question, id say its fake, the only real knowing working Portable PlayStation3 Unit was made by Ben Heck somewhere of 11 years ago, which has a Laptop shape to it, that you could cram a PS3 Hardware inside, but a PS VITA Size PS3 its out of the question.
Trivia Fact: This video was filmed around 2009,so you'd had two options back in the day either a brand new Slim CECH-2000 DYI-001 Board, or the Smallest CECHP VER-001, which both boards are too big to be trimmed down, and if you listen closely to the PS3 Buzzer you'll hear it at a distance, something tells me that its just a DUALSHOCK3 PCB Paired with a Screen and a Custom Board done by streaming, but around 2009 Streaming was pretty much unheard off,so i bet he is using an Antenna Receiver through the Analog Port, via a Custom Antenna RF Receiver through the display,which doesn't need to be connected through an RF Cable, as long as the PS3 is within range, the transmission will be displayed just fine.
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