Changing Angles captured by Andrew Kirk in the Sierra Nevadas, California.

"After a windy day the sky was full of dust. At sundown, peaks cast pronounced shadows into the dusty air. The angle of the shadow of Mount Humphreys (the triangular peak at center) changed dramatically over the eight minutes from the first to last photo.
     ©Andrew Kirk, shown with permission.

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The angle between rays cast by two adjacent peaks becomes smaller as the sun sinks.

This is purely a perspective effect. The two rays are parallel but as the sun sinks they pivot like a see-saw about the mountain peaks. Beyond the peaks they increase their distance from the ground. The rays at any given point then appear to be closer together and the angle between them is less.