In episode 7 of ユリ熊嵐 [ユリくまあらし, Yuri Kuma Arashi, Lily Bear Storm], you may have noticed this pretty pattern on the glass.
The negative space between the 鳥 [とり, tori, birds] morphs into 百合 [ゆり, yuri, lilies]. It’s a beautiful transformation. Now, the team behind ユリ熊嵐 is very creative, but here I think it’s a reference. After all the anime is chock-full of references.
This is a woodcut by M. C. Escher from 1938, where the white space between geese morphs into fish. It definitely looks similar, doesn’t it?
M. C. Escher did a large number of these “transformation prints.” To see some more visit the website of the M. C. Escher Foundation and M. C. Escher Company.