Snail shell bag? HELP!

Ok so I’m making the snail shell beach bag thats listed on this site, and I’m at the point where I want to sew one of sides of the bag together in the spiral form. I sewed but it turned out looking like a sideways spiral icecream cone…In the picture it looks so flat and pretty. What did I do wrong? Is there some trick to sewing in a spiral? Something is just not right here…

Have you blocked it? Maybe a good wet block will help flatten it out.

Bolcked it? Got it wet?!? Hmmm…these term are beyond my knowledge…please explain, thanks!

In case you didn’t see this already…someone else just asked! Here you go: