It's not the end of the world, but when adding ?mode=movie to the end of a synth's URL, we are still shown the "We can't display this as an interactive synth. See photosynth system requirements." error message.
In cases where we have loaded the page with the ?mode=movie flag explicitly added to the end of the URL, it seems like a reworded message would be in order.
A message something like, "This is a video preview of this synth. If your web browser supports WebGL, click here view the interactive synth." removes any sense that a mistake has been made on your part or your users'.