You draw the design on paper to fit the size cakes being used; cut fondant into 1" squares and apply to cake. It will take lots of time but should be somewhat easy.
There are many on-line shops that sell cake sparkles, edible glitter, and other dusts, including disco dust.
I believe those are just tiles of fondant or gumpaste. Handmade or purchased topper, covered with glitter or edible glitter. Possibly a "costume jewelry" type brooch. Poured sugar droplets.
For the 'tiling' simply use a small square-shaped fondant cutter. Color several shades of your color, and stamp out in batches and apply.
Least expensive and perhaps most accessible is Wilton brand's square fondant cutters, around $3.50 for the set and the smallest or second smallest is what you'll want to use.
I'm thinking you're wanting to know what the tendrils on this cake are made of...I checked the Pink Cakebox site, and she says they're crystals--just like the topper. My guess is that they're not edible, and therefore a no no on a cake that will be eaten unless you are the one cutting and making sure no one gets one--and still I don't think I'd chance it.
You can make the square crystals shape from poured sugar. A contestant on "Challenge" used a silicone form like an ice tray to do something very similar to this. Edible faux jewels can be found online. They look like faceted gemstones and are made of sugar. I always cringe when something inediable is used to decorate a cake unless it's obvious. I fear that someone will break a tooth or choke on small pieces that aren't meant to be served with the cake.