They appear to be going for the same sort of thing that makes those levitating globes work, with active electromagnets (in this case hiding in the thing that looks like a giant face-down iPhone on the floor) using sensor feedback to keep the unpowered floaty bit that looks like Pigsy's cloud in place.
There are two problems with the Cloud sofa.
One: It is not easy to make a stable system that can hold an object up over an electromagnet, as opposed to holding it down under one.
It certainly is possible, though; look at the Levitron Anti-Gravity Globe, for instance. As Amazon reviewers point out, though, it's a bit tricky to get the globe into the sweet spot for floating, and then any small knock or touch, or stiff breeze for that matter, will push it out of balance, with catastrophic results.
So even if the makers of the cloud-sofa went to the trouble of putting multiple coils in the base unit and huge scary rare-earth magnets in the floaty bit, the moment someone sat on the darn thing it'd crash to the ground and mash one side of itself into the base.
Two: Assuming you managed to solve the instability problem, the field strength needed to get this thing off the ground at all with a human being in it would mean the electromagnets would have to be very, very powerful. You might not quite have to cool the magnets with liquid helium, but they definitely would need some kind of bad-ass cooling, and would probably also draw a lot more power than electricity authorities are willing to deliver to a residence.
And, if you got your humungous floater magnets and 50-kilowatt lifter magnets and feedback system all in place, you'd have to make the whole room look like Magneto's plastic prison, to prevent people being nailed to the sofa-base by their belt buckle, sets of keys streaking across the room and taking someone's hand off, et cetera.
Look, I get that design students are given assignments that aren't marked by plausibility of product. But in that case, why not just make your product a teleporter, or a full-fledged antigravity flying belt, or an umbrella that turns rain into turkey sandwiches, if you don't care about making anything that can actually exist?
The hell of this is that it actually is possible to make a mag-lev lounge. And that lounge actually does look like something right out of Magneto's special jail; check it out!
The reason why this thing doesn't look very impressive compared with the Cloud is that it uses permanent magnets for levitation. There's only one way to do "proper" levitation using permanent magnets; you have to spin the levitator for stability. This is how the most famous Levitron product, the hovering top, works.
Anybody who's ever tried to get a Levitron top working will know that they're touchy little buggers - even worse than the Levitron globe - and obviously not a generally useful solution to the problem. Even if you managed to hide magnetic gyros inside a floating sofa-cloud, it'd be pretty much impossible to get the cloud to stay in place if a person tried to sit on it.
The more practical way to make a permanent-magnet levitator is to mechanically restrict the movement of the magnets in one way or another. The way of doing this that looks most like "real" levitation is to arrange your magnets so that the levitator wants to fall off in one particular direction, then put a support with some sort of low-friction bearing in the way. There are executive toys that work this way, and it can even be extended into a motor design - the solar "Mendocino Motor", for instance:
The Hoverit couch uses a much simpler arrangement, usually seen as a piston and cylinder. One magnet goes at the bottom of the cylinder, and the other one, turned to repel the cylinder magnet, is on a piston that you push down into the cylinder. This basically turns the magnets into a very-high-isolation spring, which has been used in some hilariously expensive audiophile turntables, and in add-on isolation feet for other audio components.
The Hoverit makes this look better by aligning the magnets only with the arm-rest pillars; the rest of the magnets are firmly held in the acrylic base and lounge parts, but unable to "fall off" each other because of the pillar assembly.
The result, of course, is just a bouncily-suspended hard plastic lounge chair, which I think has to be far less comfortable than a $10 banana lounge from a garage sale.
But at least it's physically possible.