eli5: How come our eyes immediately think the Scottish flag as white stripes instead of blue triangles? How come this occurs for some images and for others it doesn’t (like the flag of england?)

Question

[Click here to see the flag](https://en.wikipedia.org/wiki/Flag_of_Scotland#/media/File:Flag_of_Scotland.svg)

In: 63

Answer 1

I don’t feel I see either strips or triangles but rather the whole flag as one unit. If I concentrate I can sort of separate them out like you talk about but that is not my first instinct. Is that not the norm? I do on other pictures where it’s clear there is negative space but with this flag it’s pretty even.