UPDATE! In survival when facing the trap door player will suffocate in a block.

When i appear from the ground after opening the trap door I see the trap door directly in my face no matter where I turn. When I am no longer near the trap door it goes away.

Steps to duplicate
-open a creative world
-dig 3 or 4 blocks down
-place ladder to climb down
-place trap door near top
-climb down the later
The trap door texture will be in your face when you climb down.
-climb up the latter
-open trap door
-The trap door texture will be in your face once you make your way back to the surface!

Edit by HyperCamel:

In short, they are acting like full blocks you can pass through. You can also place ladders, vines, etc on them