It is called pleating with fondant, if you goggle it you will find a lot of different techniques and tutorials :)
Ogh. I had someone come with that exact sam pic and want a cake like that.
I think that cake is so butt-ugly, but I did a similar one and they were happy.
I almost started kicking myself for taking it. To me its a pretty easy cake, but that 4th tier scares me. Did you do it just like the pic? I posted earlier asking about structure. if you did it like the pic, how did you stabilize the 4th tier? With the one I am making, the bottom is styrofoam, so I am thinking it would give more support for dowels.
It looks like it is just has a stryofoam wedge inserted there to make it "topsy" and has flowers around it to hide the styrofoam. If it were me, that is what I would do.
That is what it is.. a styrofoam wedge underneath the cake. I have seen it done on other cakes before..