Love this idea, but removing the device (if you have to) is what rubs me the wrong way. Anyone have any idea on the implications of mounting the device, say, 3

Love this idea, but removing the device (if you have to) is what rubs me the wrong way. Anyone have any idea on the implications of mounting the device, say, 3mm away from the mirror? I think that would be about the depth of a case... and if you mount it inside a case, you can remove it seemlessly.