Well, I went with my gut and with the majority of the opinions rendered, and put the squares in the middles of the white areas. I'm not convinced that this was the right thing, but it is done now. My eye is drawn to the squares and not to the individual snapshots. But it is a baby quilt, and the baby will be viewing it at closer range, so I think it is fine.
Snapshots is a flimsy, the third of four baby quilts I will make before October to help raise awareness of The Baby Bureau.