[Nition]

Unfortunately it's too late to edit my comment now but yes, I should have been clearer that what I meant was taking a hand-held three second exposure with another camera, not that that specific photo itself would be impossible.

It's a reasonable separate point to make that a "proper" camera wouldn't need such a long exposure for the same amount of light.

[sudosysgen]

Most cameras can't, I agree, but mine does. It has a 4 exposure stacking mode, but only in JPEG mode, and the stabilization is sufficient that I can get quite sharp images at 0.8x4 handled, especially at the 35-28mm equivalent focal lengths of an iPhone.

I can share some pics, if you want. It does require a steady hand.

But then again, the iPhone doesn't really do a 3 second exposure, it rejects a lot of frame so it's more like 1.5-2 seconds, which I can do reliably.