[crazygringo]

Ah yes, I've found it -- changing "Signal" from "EM field" to "Power". That is fascinating to look at.

Is there a way to move the router around to see how the field changes in response?

As far as I can tell you can do that in the paid version, and I totally understand gating that for people modeling their own home/office layout. But it would be pretty cool as a free educational demo if you could move the router in the otherwise fixed example.