HTMLspeak (coding): a "page" has a fairly specific definition, (or a few fairly specific definitions).
Webspeak (viewing): a "page" is whatever downloads when you click a single link and is viewable until you execute a new link or jump to a new web address (url).
We often don't announce which language we're speaking - or when we change to a new one.
Jon was pretty broad-brush there, but he probably grinned secretely.