I would love to know the physics here. I had a Xiaomi phone a couple years back that had a glass back and would do this as well. It's been a while so I don't remember details, but is it just because the surface it's resting on isn't completely level?

At 2:50 the person puts the level on the book, and it's clearly not level. It's not badly off, but then again, the phone doesn't move really fast.

When the phone is on the level table, it's also not moving, but maybe the surface is not as smooth as the book.

In addition, putting on a bunch of cards that are extremely light showing they don't move doesn't prove anything, even if you stack them up.

It would have been better if the video started out with the level on the book at all times, and showed an item of similar weight on the book that doesn't move. This feels manipulated.

I can't keep mine anywhere. I slides off my leg, my desk, the arm of my recliner, my center console, and my bed. I hate glass phones and I'm not 100% sure what possessed me to buy this one. I can't stand cases either, so I guess I'm stuck with it until it leaps to its death.

I had a phone a few years ago that did this. The back was glass and it just made it incredibly slippery against all other surfaces except for hands. The tiniest imbalance would eventually cause it to fall off of things. Pretty annoying; just have to be aware of it.

My iPhone se 2 does this, but my galaxy 8 didn’t. I wonder if it’s a glass thing.

Interesting, but doubtful more than a parlour trick, until further analysis shows work.

A laser interferometer, or perhaps a puddle of mercury could reveal what's virbrating and why.

The video can't really prove anything on its own, since statistically, we have no way to intuit your character, potential motivation or reputation (hn karma lol). It's too easy to David Blaine something like this, but if 1000 other people quickly discover and replicate the problem, and converge on a pattern, then you get extra credit for discovery.

How do we know it's not environmental? The heavy mass and smoothness of the metal/glass phone against the friction profile of the un-dust-jacketed book cover is going to behave differently than plastic credit cards which are rougher than glass, and have a mas of only a few grams.

It could be infrasound from a nearby subwoofer, an unlevel plane by microns, capacitor whine within the phone, the phone's haptic motor on the fritz, anything.

Cute trick. Instructions unclear.

See also: https://en.wikipedia.org/wiki/Gauge_block

Lots of phones and tablets do this. This isn't a new phenomenon by any means. It's annoying but it isn't controversial or anything. You want a smooth sleek phone or tablet, this is one part of the price you pay for that.