Swap textures if only 1 face visible


Hi there,

Working on a new filter. I have 2 images 'floating' and each has a face inset attached. The problem I have, the moment there's only 1 person, second face completely disappears so empty body is floating around. How do I program it so if there's only 1 face visible, either the textures of the floating image changes (for example it switches to a texture that already has a random face texture on it) OR if only 1 face is visible, both insets use the same Face texture?
Still new to Lens Studio!