Every once in a while, because of the sun angle through the figmented window above the staircase, one of the flowers will appear to be radiating light. In this case, it is a pink Asian lily that produces the special effect. The yellow pigment near the center of the lily almost makes it look like it’s on fire. You can click on the image below to enlarge it.
A while back, I took a photo of an Easter Lily in which this effect was considerably more dramatic. There is also another nice Easter lily effect here.