The rule for "Extra movement to line up in close combat or in a TZ" (p.33) says that "A contacting, contacted or TZ-ed element or group that is not lined up moves up to an extra base width (80p) to do so if the extra movement is used only to line up with an enemy front, flank or rear edge".
There is nothing specifically in that wording that limits contact to only being by an edge. Contact by a corner would seem to suffice, as long as the additional 80p is then enough to get you into proper front edge combat (it won't always be enough, as a little fun with Pythagoras etc will demonstrate).
FWIW, I have come to the conclusion that if you can contact with a corner, you can then use the extra 80p pivot/shift/wobble to line up your front edge in combat in one of the situations further up on p.33.
Tim Child