Mama, what is this?

Mother replied him that this thing is used for washing the window when he asked. He immediately used it to wash our house's window which he washed the mosquito net inside the window part. Seems he likes and in order to make him understand the function of this stuff, mother went and gotten one red bucket of water and asked him to wash the outside window. He did it and he thought it was fun.

And what you see in the photo is him seriously washing the window. The funny part was he even went to pull the stool and stood on it so he can wash the upper part of the window.