I Can't See You

I think I see how it's done. Note that the background usually consists of horizontal bands, e.g., walls with horizontal stripes, seashores, etc. A lot of vertically oriented cylindrical lenses would give you the effect of concentrating horizontal features and hiding other features (namely, you).

It's easy to hide. The trick is hiding (or camouflaging) the cloak you're hiding behind.

From what I saw, movement will give it away, and one cannot see out from behind the cloak, there must be a peephole somewhere. Of course, one could wear smart goggles that would let him see the surroundings from a different perspective, like perhaps a drone or other well placed camera, even a fiberoptic lens.

It looks like the edges are blended with the surroundings also, especially in a feature rich background, like the man in the camo suit, but even better. The shield can even hide infrared, which is a sniper's worst enemy.

All this tech may eventually be rendered moot. The next real war will be fought with software.

With nearly all the world now dependent on computers, hardly anyone can still do it the manual or analog way. Old Pharts like me will eventually evaporate, taking all of their "ancient technology" with them.

OR perhaps a a large CME will destroy all of the critical components

That will thrust the world back to the stone age.

As Albert Einstein said "I don't know what WW3 will be fought with ,but WW4 will be fought with stick and stones."

Here's one done with mirrors, no smoke. It's not very portable, but pretty realistic.

These guys are the experts at camouflage.

https://ocean.si.edu/ocean-life/invertebrates/how-octopuses-and-squids-change-color

Read the mind of a sleeping octopus...