I’m not sure what are you complaining about here. It seems to me it does exactly what you are telling it to. What outcome did you expect?
Edit: I think you need to check some tuts on how to use grid panel because the initial setup of 1, 2, 3, 4 you are assigning to rows and columns is probably not what you want. Try to use values 1, 1, 1, 1 for both of those if you want uniform grid.
The screenshot is not clear.If I change the position of the button, the size of the Image below will change.
Change the 0 values to something else