Could that be a reflection of the sun?
I do not think so.
I've watched a couple of snaps
and it looks like fire . . .
"This is an image of Mount St. Helens, taken from the Johnston Ridge Observatory. The Observatory and VolcanoCam are located at an elevation of approximately 4,500 feet, about five miles from the volcano. You are looking approximately south-southeast across the North Fork Toutle River Valley."
Possibly.