What does the imagery on a tomb mean? Meleager of Gadara here plays with the decoding of relatively traditional symbolism and reinvents its meaning to be appropriate for another poet Antipater of Sidon, while at the same time mocking the man and his art. The joke in this poem turns on the specialized, atypical meanings given to the very typical images. I’ve discussed cocks elsewhere on this blog: they often mean martial 
prowess and are combined with typical images of victory like the palm or wreath.
Knucklebones are also very common images on funerary monuments especially of children:
Elsewhere, they may symbolize chance or fate.
In a much more general sense this type of joking reading of familiar iconography is helpful to the numismatist because it confirms the visual literacy of the ancient audience.
Liv Mariah Yarrow 