Those are clouds.  But believe what you want to believe.

Wow.  Talk about what you WANT to believe.  Those mountains at Canagal are a known phenomenon, and it only happens on a few days of the year but it's consistent, and evidently just to mess with us God will create an outline with clouds (just during those times of the year) that happen to match the exact contour known contour of the mountains.

This here is all the proof you need that some people just refuse to shake the programming from their cold dead brains, absolutely refusing to listen to reason and examine the evidence.

You'd be much better off attempting to play the refraction card ...

Another thought.  How far are those mountains from where the person is standing?  If it is less than 3000 miles there is no way the sun would be lighting them up from behind, since the sun travels parallel to a flat earth.  

So ... you've made it abundantly clear that you simply don't want to accept that the earth might be flat.

1) that's just clouds (just blurted out without any evidence or analysis)

-- yes, the exact same cloud formation that just happens to re-appear during about the same time window every year and each year just magically happens to follow the exact contour of the mountain range that just so happens to be in that same place.  You'd be more ready to believe that than than that the earth might be flat?

2) I did some geomery ... and scrawling out some numbers that are not relevant to the specific example in the video "have you ever seen a plane?" ... reminding me of another poster's "have you ever seen a sunset?" nonsense

-- yes, the geometry of earth curvature is well known, and there are calculators online (not created by FEs) that will calculate the "hidden height" of an object based on the elevation (above sea level) of the observer, the height (above sea level) of the target object, and the distance between the observer and the target object.  In the video, the numbers were run, and the entire mountain range should be hidden by at least 3,000 feet above the heightest peak, and it's clear that all but about 1,000 feet are visible (for which there can be many explanations, such as the topography between you and the target, ocean waves, atmospheric conditions, etc.).  What's interesting about this phenomenon is that the angle of the sun cuts through those atmospheric conditions that would normally block your ability to see the mountains from that far away.