https://people.math.ethz.ch/~acannas/Outreach/ctt_simetria_passo_a_...

... symmetry of the kaleidoscope image in figure 102 is  3 3 3, since it exhibits three different centers, in ... . Therefore we say that its symmetry has signature  5. The image of this kaleidoscope exhibits three types of ... symmetry of the kaleidoscope image in figure 102 is  3 3 3, since it exhibits three different centers, in ... . Therefore we say that its symmetry has signature  5. The image of this kaleidoscope exhibits three types of ...