Architectural detail: Welcome to my vortex

It feels like I've seen this a lot in the past week: distorted perspective entryways.

[The Long Studio via Remodelista]

[Project House GS via freshome]

[Project House GS via freshome]

I don't have a lot to add, other than to point out that even though it feels really open, it's actually a very private entrance.  Especially in the second project.

Also, it seems like a good place to paint a giant swirl around and around.  Except I think everyone that passes through would get dizzy and fall down.