It's just an over simplified illustration that shows how a dog is a product of nature (genetics) *and* nurture but that you cannot "nurture" (train and socialize) a dog outside of its genetic boundaries. The green and blue show that you could have the same dog end up a little differently if it was raised by a different person, but never outside of the genetic boundary.
Liesje & the K9s
Nikon (GSD) U-CH SG Alta-Tollhaus Bono SchH1 KKL T1 FO PA TF-III FDCh-S CL1-R UJJ U-CA HIT TT CGC
Coke (All-American) VPC's Coca-Cola CGC, couch warmer extraordinaire
Indy (All-American) Blue Horizon's Indigo Girl, flyball star in training
Rainbow Bridge Kenya (GSD) U-CH Alta-Tollhaus-Krieger Lamb Chop CL1-R CL1-F RA HIT TDI TT CGC
vom Blauen Horizont / Blue Horizon GSDs