One of my dogs was was a clunky, happy-go-lucky lug of a dog who took up too much of the path as far as our other smaller dog was concerned. Twice, I remember, the smaller cattle dog needed to get around the larger lab: the easiest path was simply to go under him!! The smaller dog just slithered through without disturbing the larger dog at all. The smaller cattle dog weighed about 50 pounds — not such a small dog; the larger lab weighed about 90 pounds.
So when I saw one coyote pass under another, I was reminded of my own two dogs. But in this case, the coyote passing under was actually the larger of the two and lifted the other one up high — it was not as smooth an operation as with my own dogs!!