Both of these two strollers, the Jet and the Wing, are ultracompacts, meaning small, travel strollers for rather occasional use. Voth are small, with a smaller seat that's on the slanted side, and both fit the cabin luggage size pretty much.
The main difference between them is actually the folding system, which, with the Jet, is 3D, meaning more joints and more places the stroller is folded in. It means a slightly smaller fold, but also a looser chassis. The Wing's frame is folded in 2 sets of side joints, meaning just a flat fold, and even though I cannot say the frame is sturdy (it is a small buggy, and not that durable, to be honest), it is definitely sturdier than the Jet.
The Wing has also a bit large basket space, and the canopy shape is also a bit different (With a small mesh on the Wing (2)), but that is not much of a functional difference, really.