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 & pack
Coke (All-American 7/7/06) couch warmer extraordinaire
Nikon (GSD 9/7/08) U-CH SG SCHH1 KKL1 T1 FO PA TFE-II FDCh-S CL1-R UJJ U-CA HIT TT CGC
Indy (All-American 5/10/12) flyball star in training
Legend (GSD 10/22/13) the legacy continues...
Rainbow Bridge Kenya (GSD) U-CH FO OB1 CL1-R CL1-F RA HIT TDI TT CGC