That cake was made by Mike's Amazing Cakes. It looks to me like they were made of modeling chocolate. But Mike is very good at responding e-mails. Maybe you could ask him.
I just did a search for gumpaste people mold and got several sites that carry them...various sizes too....
I agree with pp...MM has stated his preference to using modeling chocolate...but they can definitely be made with gumpaste as well without a problem, if using a mold.
I knew it was a Mike's cake. I shoot him an email. Will you post the sites where you found the molds?
The reason I said I did a search was 'cause some of the sites won't post 'cause of the 'ban'
su gar c r a f t dot c o m is one
actually, they had the widest variety
this is the list of results from me typing in gumpaste people mold
browse through the results
I want to know how in the heck, you get the top tier to slant like that and not fall!!!!