The beautiful symmetry art under this line are... and are not... tessellations. As abstract shapes,
they tessellate: they cover a flat area without gaps or overlaps, like bricks do.
After the children put in details like water, air, and faces ... then this art ceased to be tessellation.
"Without gaps or overlaps" is the key phrase. Air and water have no definite shape or size, so they're background... they're gaps. Zack's "Lightning & Ocean" and Kaylee's "Pretty Peace Signs" are the perfect examples. As abstract tessellation, they are undeniably perfect tessellation with admirable engineering precision. When we're told Zack's is air and water, though... air and water are formless gap-fillers, so suddenly Zack's perfect tessellation ...isn't. And the border around the peace signs is arbitrary-- nothing about a peace sign insists that it should have a jagged sawtooth-like squarish border, right? Kaylee's art, when she added the peace signs, became far more beautiful-- I'd happily frame it and put it on my wall-- but it stopped being a tessellation, except as an abstract tessellation. Art rules are weird, huh. I guess that's why so many great artists like Picasso and the Dadaists love to defy rules.
We could also say that the "face & head" art like "King and servant", above, is...and isn't... tessellation: A happy face implies that there is a happy body attached to it, right? So, where are the bodies? Are the bodies hidden behind other heads, like the audience at a movie? That's overlapping... and overlapping isn't in tessellation. We're used to seeing heads without bodies, though... in Roman sculptures and portrait photography, for example.
Thanks for looking at the Zaneis Wildcats' art. We should be especially appreciative of this art: Cats don't have thumbs or even monkey tails, so they can't easily hold pens and crayons. I guess they use their teeth. Tessellations are hard; symmetry art from young cats is double-tough.