At this moment Screen Tap also responds to the Image Tap. So if you tap the Image (related to the Image Tap) the app also triggers Screen Tap (since the screen is tapped). It limits the capabilities of using these both in one effect.
The good practice is to separate those taps. So Screen Tap would trigger only when the Screen is tapped outside the boundaries of an Image, and wouldn’t react if the the tap is within the Image Tap area.