In a recent post about the Ministry of Magic queue at Epic Universe, a preview guest posted a theory that the illusion of the interior of the MoM may be achieved by using mirrors, which got me thinking about using mirrors at a large scale, and reminded me of a building I've long been fascinated by on Cauhenga Blvd. near Universal Studios Hollywood because of the visual trick it plays. By combining a mirrored surface with an outward angle, it reflects the street below in an unexpected way: when you look at the building you see cars driving by.
That made me wonder: could mirrored surfaces be used to hide buildings? (e.g., show buildings and backstage buildings in general)? With some research I found some examples of how mirrored surfaces can make a building nearly disappear or diminish it greatly, by reflecting the sky, surroundings, trees, etc.. Here are examples.
So, the the idea here is that an exterior surface material commonly used on office buildings, perhaps with a slight angle either to reflect the sky or reflect the landscaping below the building, could be used to "hide" the building. I'm not sure this has been done in theme parks but "hiding buildings" is not a common goal in architecture! (Except in some of the nature-setting buildings in these examples where the goal is to not spoil the views.)
I did a diagram using an Epic Universe building to show how the effect could be used someday.