Wull, I have not seen this picture but I have some ideas for you. Now if you are just wanting to be a chocolate purist, get your choc the correct temperature and use a spoon and scoop up petal shaped kina free form petals. You could actually pour out your choco and wait till it starts setting up and touch it with a teardrop cutter and then scoop that up. Have fun. Or or or you might want to use what some people call candy clay in order to roll the chocolate out and use cutters similar to what B Keith recommends. Candy clay is 14 oz of chocolate or candy melts melted & add one third cup of corn syrup, slowly stir together. I let mine sit in the container that I melted it in and smooth it all level on top or it separates. Cover well & let that harden overnight and pinch off & knead it in small portions to soften. If it does separate, just knead it all back together. So you can use candy clay to make rose petals - but not super thin ones. Or or or - But if I wanted a melty in your mouth candy to look like real translucent petals I would use two parts marshmallow fondant and one part candy clay. Marshmallow fondant is nothing more than a 16 oz bag of marshmallows melted with two tablespoons of water and add two pounds of confectioners sugar - so put one pound of sugar in a bowl, pour in the melted marshmallows & water and any flavoring, mix and add the other pound of sugar - you will need to micro-zap this a few seconds (like 5-6 seconds) here & there to loosen it up so you can knead it all in. So combine 2 parts mmf with 1 part candy clay. You can now roll this out nice & thin :). You can now cut out a teardrop shape. Put this on a cushy placemat or spongy thing, actually this is pretty important for success - it's called a celpad - get it at a cake deco store ten bucks maybe - dust with cornstarch first - take a ball tool which is a dowel with a ball bearing on each end - or just use a marble or ball bearing - and run it over the edge of the petal that is sitting on the celpad to thin the edge to remove the just cut look - then rub the marble over the belly of the petal and it pops up just like a rose petal - sit it in a spoon to let dry. Wa - a - a - la - yummy candy rose petals. Oh yah and you can flavor these however you want too. You can color the dough with food color or airbrush afterwards, and/or brush with petal dusts also available at cake deco stores. Getcha' some super pearl dust at least and brush that over the finished product.