They're all very good, how a key and lock work together, how Eskimo pies are produced, chains, zippers, pasta, a slinky falling is interesting, how a dog laps water, but one item I noticed on the third page is a GIF file but not animated and does convey the idea but not so perfectly shown.
They did say "perfectly."
They show a few things in nature, sunrise to sunset, flower blooming, insects doing things and the like, but they don't show a hummingbird's drinking. The bird actually shoves two tongues into flowers and uses the edges of the inside of flower's structure, whatever that might be (shown with a glass tube) to grab a portion of a droplet of nectar. I saw video clip on Reddit tonight. The closeup portion shows the two tongues ragged at their tips like split end hair. I showed this before but that video isn't so clear, not quite as good photography as this.
Ah, found it here linked on Reddit to Imgur. I think it's a good video.
It's a very strange tongue, a strange construction. And a strange way to sip. And the action is unbelievably fast. Fifteen sips per second. Wikipedia says they flap their wings 50 times a second. The videos show the wings too and in a few it looks to me like the sips go faster than the wings. There are a bunch of videos now. They all take a slightly different approach in showing it. So it's not just me fascinated by this bird.
[hummingbird's tongue] I think the video on Imgur is best.