[mistercow]

"Multiple pepper's ghost displays stacked up" doesn't really make sense. Pepper's ghost requires a lot of space, and it isn't really stackable.

[sp332]

You're right. Each display uses diffuse instead of specular reflections. That way each pixel that gets projected onto the screen shines in all directions.

[achr2]

It's a very similar effect except the image in projected onto the glass 'reflectors' directly.