Is the interference from leaking microwaves themselves or resonant leakage from the magnetron and/or support circuitry which is desired to be as cheap as possib

Is the interference from leaking microwaves themselves or resonant leakage from the magnetron and/or support circuitry which is desired to be as cheap as possible? Also you can’t really see the cage: that mesh you see in the window is indeed designed to block emission, but in a cheap one you can often see a gap between the mesh and the bezel, and of course the shell is a cheaply assembled rectangle without tight corner fittings so is probably leaking a small amount here, especially at the back, where they assume a wall will catch any leaks.