Tress spoke with children about their dreams—often nightmares that involved falling, monsters, that buried alive scenario—and would then photograph them experiencing it in a safe, staged setting.
"I was looking for mythological, archetypical, kind of nightmarish images. That kind of became my trademark for the next 20 years, that kind of surreal disturbing photography."
That link and this one have more examples.
(thanks to Randy McCall!)