Australia or New Zealand?
2 flags that get mixed up with each other. The two hardest are Australia and New Zealand — 66.4 apart, where two copies of one picture score 0.
Every pair, measured
Nearest first. 0 is the same picture; the number is the worst single tile, out of 255.
What they have in common
Every flag in this group was measured as a single-coloured ground, a canton.