I just noticed in my Facebook uploads that for my videos, it says I have 25本. What's the reasoning behind using 〜本 to count videos or movie clips? The only line of reasoning I can come up with would be thinking of the the movies as as old reel of actual film

Even though they are circular, they are more flat than long, so I would think those would be counted as 〜枚 instead of 〜本.
So what's the reasoning for using 〜本?