Cool. I never thought about it before ... from Mercury, the Earth/Moon would look like a double planet, although the moon would be far dimmer(the surface of the moon only reflects 1/3 the light of the earth, per square foot, and has less than 1/13 the apparent area, so it would be about 1/40 as bright as the earth, but still visible by the naked eye)
as the distance from the earth to the moon is 30X the earths diameter, this picture shows the moon as it just about to go behind the earth/just came out from behind the earth/just about to go in front of the earth/just came out from in front of the earth.
also I would assume that the atmosphere free extremely white moon would reflect more of the suns light per square foot than the earth with its blue oceans and diffusing atmosphere....