The website says it’s the world’s first projection art festival, so yeah, they use projection.
“Festival organizers said they mostly use consumer-grade projection equipment for the event, but do it on a large scale with about 50 projectors in play at a time.
They are mostly HD-capable LCD projectors designed for small- to medium-size theatre or conference room applications,” said event organizer Scott Stephens. “All artist submissions are required in a QuickTime file format to certain specifications for optimal projection.”
Thanks for making me aware. Some of those pictures were amazing, very cool. :)