As a starter, this mink is not in distress, no matter what it may look like from some of the photos.
It's Spring and I think it was a combination of cleaning out that Winter coat and a re-oiling process of its fur after swimming and fishing.
And what better way to get those unreachable places but to rub both topside & underside along an accommodating log, particularly when you have such short legs like the mink. From some of those expressions, I think it was a combination of feelings of relief and jubilation.
And those looks can range from "cuteness" to "look out - predator on the loose"!