aosaigh

I'm trying to "cut out" one shape from another using subtraction. In this case, I want to cut out the "Heinz" text from the background black shape. This only works whe the top shape (the Heinz text) is partially outside of of the bottom shape (you'll see me try this first in the GIF below). When the top shape (Heinz) is completely within the bottom shape, the subtraction doesn't work. Why is this?