One of the harder things to do when looking at mushroom, is seeing the underside. The underside is very important in identifying some of the species. With very small ones like the one above, which is about an inch high, without picking it it is basically impossible.

Go in as close as possible with camera and frame the mirror and take the image.

By cropping the photograph, you can get a reasonable photograph without disturbing the fungi. This image was made this way from the mirror shot.