Do you know what is the sign for elevator or lift? Or how should it be?

I have to admit I stood before this sign for half a minute before I got it.

It's for the elevator (lift). I wonder why this happened? Have I never seen such sign before? I probably did, but I haven't paid attention to it or it could have had a word Elevetor or Lift by it. Anyway, I'm not alone.

I wondered about other signs for lifts. Here are some I found on the net (sorry for the stock photos ..) and I'm still not sure which one I prefer. I like the one with buttons or the happy couple (although the happy couple would make me wonder and wander as well).

Definitely not this one with two people and a roof above and below them.

This one has buttons and Elevator word ...

And I'm not sure if this is my mental map of a lift!!!?!?!

This one has even sliding doors opening (or closing)