I'm in a meeting and can't see my colleague's video, but she can see and hear me just fine
The truth is, this might occasionally happen: there will be a time when you cannot see or hear your colleague, but she can see and hear you just fine. Or, vice versa.
Likely what has happened, for whatever reason, is that you or your colleague got disconnected from our media server.
There is an easy fix for this: force a reconnect to the sever. Refreshing your browser, logging out and back in or moving to another room and back again all cause reconnects and nine times out of ten fix any media issues.
Another more graceful and less disruptive way to reconnect is to right-click on your avatar and select Refresh your media.