They say that this can be used to safely move injured soldiers out of the battelfield. I am having hard time understanding that. From the looks of it, this see

They say that this can be used to safely move injured soldiers out of the battelfield. I am having hard time understanding that. From the looks of it, this seems like something that dwells in well with the background. Moving subject will definitely be visible as background doesn't stay constant isn't it? But this is definitely something very innovative and unique.