What is this key for on my keyboard?

[Alessandroin]

Upper left corner

[#2]

@Alessandroin 

I never seen such keyboard!

[#3]

I guess it's a copy key

[#4]

@Alessandroin 

On most keyboards this place is ( ESC )

[#5]

It should be ( ESC ) key.

[#6]

I think it's the print key.

[#7]

It is a key for mirroring.

[#8]

I don't have such one. I guess it is for a copy or screenshot or task switch.

[#9]

Go to the manufactuers website and download the user manual. You will find what this key is used for.