Yeah the corner can correspond to any one point on the torus. They are all the same point, but other than that there's nothing really interesting about the corner(s).
The edges are more interesting, two of them go around the 'hole' of the 'donut' and the other two wrap 'around' the 'donut' itself (i.e. around the dough if it was an actual american style donut). There's no way to tell which is which.
These edges have the interesting property that you can't shrink them to a point (compared to say a loop on a globe which you can make smaller until its a single point). Except when the donut is not hollow in that case one of the loops becomes contractible, turning the space into the equivalent of a circle.
The edges are more interesting, two of them go around the 'hole' of the 'donut' and the other two wrap 'around' the 'donut' itself (i.e. around the dough if it was an actual american style donut). There's no way to tell which is which.
These edges have the interesting property that you can't shrink them to a point (compared to say a loop on a globe which you can make smaller until its a single point). Except when the donut is not hollow in that case one of the loops becomes contractible, turning the space into the equivalent of a circle.