Even at his worst case (all images are 1mb) - they're only serving ~1tb per month in image data (admittedly, he mentioned these were stale numbers, so it'll have increased since then).
But I serve 1tb/month (actually much more than this) on old gaming machines sitting in my basement with just a standard comcast business line, just hosting media for my extended family.
I pay 200/m for the business line, and then another 15 in electric costs. And I need the internet either way.
Every now and then I get a rep calling trying to upsell me, and that's about it.
At the end of 2 years they wanted to renew me. So my strong suspicion is they don't care in the slightest.
I'll add - I've also done this on a consumer Google Fiber line (which is more restrictive in the sense that contractually I can't host paid services). They also don't blink an eye when I push out 10mbps (or 500mpbs) over extended periods.