Isn't masking tape the one that looks kinda like sticky yellow/beige paper? I think you're right about tape being used, but it's one of the clear ones.

I also counted at least three of the plastic ones that get nailed to the wall. One near your first picture, (can't see it while I write this comment (really need to get a better client than Voyager) so I forget if it's visible in the pic or if you need to check the big pic), on the cable from the PS4 to the TV, just after the bend to a diagonal, it's one of the ones you clip the cable into after mounting. And two on the xbox psu cable, they are both the type that you nail over the wire and a curved bit of plastic holds the wire against the wall.

But those were the only ones I could see, plus even those ones don't explain how it keeps the hard angles instead of the cable settling into a rounded shape. Guessing they intended to use the plastic ones but quickly realized it wouldn't hold the shape they wanted without needing to put a ton of holes in the wall and switched to tape after that to solve both problems.

Edit: looking at it again, I don't think the first one I mentioned is one of those clips anymore, so just the two on the xbox psu cable (should be obvious once you see them).