In my experience it is over the span so there is no sharp "pivot". Washout is usually a small angle (2-3 degrees) so it is not really visible unless you look at the wing from the trailing edge. There are 2 ways washout is generally applied. The first is built in where the foam cores are cut or the wing is built blocked up slightly to include the desired angle. The second is less scientific and involes manually twisting the wing while shrinking the covering.