Photogenic means 'attractive when photographed'. Strictly speaking, 'faces of a pentagon' is meaningless : pentagons have no faces, as they are two-dimensional. However, they are trying to say "something pretty with five sides".

It is puzzling. The writer is using words in an unusual and creative way. I don't really understand it myself. Usually the word "photogenic" has a specific meaning. Usually it means "a person who looks good in photographs." I don't understand how you could photograph a "fortissimo," either. A "fortissimo" is the sound of a musical passage when played as loudly as possible.