(author here) I believe I had checked first in this case, which is why it was surprising. Sorry not to mention that in the post. This was in San Francisco, and there were multiple cars shown on the map.

In my experience, I usually don't see this kind of price change before the request has actually been confirmed - and I have seen Lyft change the price between showing me the estimate and confirming the request (with an apologetic confirmation dialog, possibly only after some holding period has timed out).

Maybe in my case where the high quote came first, the opposite scenario happened - a glut of drivers appeared between my request and hers, raising supply.

Opaque pricing is powerful partly because we don't know. This enables people to construct a plausible story to explain any price.