Maybe I missed something, but many many photos in triptych are 720px on one side. I know there's a poll about increasing size.. However there was no rule change thread and it Clearly states 640px in rules...
Extra rules apply to this challenge You may use up to three photographs for this challenge, as long as the combination of the three meets the file size and dimension restrictions.
Please note that the file size and dimensions restrictions have been increased for this challenge.
See the yellow flag indicating special rules? You didn't read the challenge description. "Please note that the file size and dimensions restrictions have been increased for this challenge."
Since Langdon changed the rules on that challenge. People complained that 640 wasn't big enough. It is not for the basic rule set. Just that particular challenge.
