Cf. these glass pastes from the British Museum:
I don’t think this above is likes to be for a ‘Crassipus’ The symbolism seems to rest less in the foot than in the hand and butterfly that work together to bind the laces. The butterfly represents the soul (psyche, anima). Perhaps the message is a sort of hard work, and innate ability together produce results….
This is a top view of foot it could be for a Crassipes, but equally it would be joking with the idea of leaving a footprint/leaving one’s mark and the function of a seal ring. Although for that we might expect a bottom view not a top view.