by Kimseang C.
This is tessellation shows translation symmetry, also called "slide symmetry" and "glide symmetry".
Technically, tessellations should not overlap. So, if we look at these fan / fish scale shapes as abstract,
then this is a tessellation. If, however, we imagine that each penguin's feet are hidden behind the penguins
standing in front of her, then this is not a tessellation. Tricky rules, huh!