Princess Diana piercing resembles a vertical clitoral hood piercing.
This involves 2 piercings, to the left and right of the clitoris, running through the clitoral hood.
Unlike a VCH you will have 2 piercings, to the right and left of the clitoris, instead of a single ball on the clitoris.
Princess Diana piercings are usually performed in pairs and may be an addition to a VCH. They’re essentially VCH piercings but done off to the sides. If you have a VCH, you might flank it with Princess Diana Piercings.