A puzzle

This piece by Daniel Olsen is currently on the wall of the Mercer Union gallery, part of the Infinity Etc. show, which closes on Saturday.

The digits are arranged in a sequence. Can you figure out what kind of order they're in?

For a hint, highlight the following invisible text: The answer is very simple; it's kind of a trick question. Also: The sequence only works in English.

Update: Still stumped? Click on the photo to go to its Flickr page, where an alert Flickrite has posted the correct answer in the comments -- scroll down, you'll find it.