e.g. when i'm preparing and sorting out the photos to post on my webpage i do this in rows of 4. and for that reason i always drag the photos to the position where they should be to get a better picture how they will look and fit online lateron. unfortunately this feature is not available with xnview
maybe this might be an idea of a new feature?
a feature like that can be found in acdsee and also in faststone image viewer...