spacetime in light

one of many variations i did on "the sleeping room". i was passing out as i was trying to finish it up, saved and exited without saving the history, so i really don't know for sure how i got that [sorta transdimensional] effect. i spent many hours trying to comb my fuzzy memory and successive approximations to reproduce it. i came up with a couple by different routes that were close, but couldn't nail it. some things must remain a mystery...