Call of Duty Nacht Der Untoten ee?

[Perplex]

Well i was outside of the map and threw a molotov at the roof and realized it had writing...

It says caulk" and "shadow" everywhere
Anyone know what this is?

 

[Damian]

After looking around fairly quickly it's just apparently an easter egg or something.
There's some recorded videos of it on YouTube and such.

 

[Kurumi]

It looks like an easter egg to me.