I found a couple of tutorials on how to make the rose petals,
Hope this helps with the petal part of the cake.
It's very easy to make rose petals like that. You need to roll out the gp or fondant w/some Tylose or GumTex added thin & cut w/ any general petal cutter. Then all you need do is soften/lightly ruffle the edge. It looks to me like they might have lightly dusted the edge w/a bit of silver dust too.
Get an apple separator from a grocer store and dry those petals in it.