How can I make this cool chocolate shape?
I think it is more likely that the pastry chef employed a piece of food grade acetate (the link is a sample vendor).

They would have piped the pattern of tempered white chocolate onto the acetate sheet, then rolled it into a cylinder (chocolate on the inside) taping or clamping it shut to set.  Once thoroughly chilled, they would have very, very carefully peeled the sheet from the chocolate.

This is a very advanced technique, especially with white chocolate, which is persnickety and tough to temper, and often not as solid as dark chocolate.  Good luck.