^ unless they are 2 different widths it is most likely the black were pulled tighter to the last when hand lasted. They look like they are both SD lasts from above (side shot would confirm). The toe cap always makes them look overly bulbous with a thicker leather anyway Imo. To the trained eye no 2 pairs of the same build often look exactly the same. Different bootmakers in the workshop and different leathers = varying results. Construction and comfort always top notch though that's why I continue to sell and wear them. You'll see some of the above from Viberg etc.. As well.
Could be different widths. But the 2nd picture shows more clearly a very obvious curve going to the right on the brown boot which I cannot understand how that would happen unless it was built on a different last. Again this is my first time buying White's so I am still learning here..