Not geneticist, but this appears to be a metaphor for "punnet squares". These are the box diagrams that purport to show the percentages of different genetic traits based on mixes of dominant and recessive genes.

Again, not a scientist, but this is the stuff we learned in the 80s in science class, before the human genome project was even undertaken. The reality now, I'm fairly certain, is that even something as simple as eye color actually has a lot more complexity behind it than these simple boxes. And the expression of genes and the proteins they code for depend on the interaction of a lot of processes, many of which we don't have a complete picture of yet.