If it was me I would just ice a cake, kind of smooth but just spatula smooth. Not viva or roller smooth. Then I would take a knife with a point, balance my forearm on a box or something to stabilize it a little and give the turntable a spin, pushing the knife point in a little then gradually go up. Or down depending on if you started at the top or bottom. Just my guess, anyway.
Is that BURLAP around the bottom??? Pretty cake, but is that really burlap???
Let's hope the burlap was backed with a strip of wax or parchment paper or saran wrap to keep the burlap fuzzies out of the icing.
Interesting that you posted this, I just watched a video on this very technique yesterday. It is from a fellow cc'er; costumeczar. She has several youtube videos that I have found to be helpful. (Thanks costumeczar!)
*Mod edit - please embed You Tube Videos here by clicking the filmstrip icon above and adding your hyperlink. Thanks!