She Sells Sea Shells is a repeating design of clamshells, or maybe fish-scales. When you look straight down on it all the shapes look the same. When you look at it from an angle you see some shells as being dark and others as light.
These shells are very interesting shapes to work with as the cushion can be made in one piece with almost no ends to darn in. The curves are created as if by magic. They work particularly well for anything that can be joined into a cylinder so would also be good for bags. The pattern shows some arrangements that could be used for afghans although there are drawbacks to using the shells for flat items as there will always be irregular edges and there is much more stopping and starting in the construction.
We know someone who made this as their first ever knitting project though we would not generally recommend it for absolute beginners. Just a little experience is necessary.
As with all illusion knits, the illusion is clearest when the knitting is completely flat.