A number of people have wondered how it was possible to line up on the wrong runway.
I read on another forum that runway 22 dips towards the SW; so when lining up it looks shorter than it is because half of it is hidden from view.
Similarly 26 has a shoulder so doesn't look any narrower. In the semi-light of the morning there would therefore be few visual clues that a mistake had been made. The only clue would have been the heading indicator.
I am surprised ATC didn't notice though.