What is this floor?

This is an example of the signs located at the mid-point of every flight of stairs in my building in Shida, which inform about the upper and lower floor numbers.

There are many similar to this one everywhere. Sometimes, it seems like there are more than the proper floor signs. They can be more or less elaborate or fancy, but I had never seen any of this type anywhere else. They are very useful to know where you are if you are climbing the stairs and lose track of the floor number.