I only have a B.S. (physics)... but I'd say that the illustrations aren't factual. All of the text, however, is spot on.

Unfortunately, It's kind of a ridiculous notion in the first place, to try to "translate" WiFi to the visible spectrum. The way frequencies outside of the visible spectrum behave would be startling, if you were suddenly able to see or sense them via an integrated biological mechanism. One striking example is that if you were able to detect UV, you wouldn't be able to see through water further than an inch or so. The ways that various frequencies are absorbed, reflected, transmitted, refracted, etc. are totally foreign to the human eye.

Consider a light bulb as analogous to a WiFi emitter. Do you see the actual propagation of the waves, like in the second picture (the WiFi sources reside off the edges of the illustration)? No, you see photons from the light bulb, and what's reflected from the surrounding surfaces. If you could "see" WiFi, it would be similar. Granted, I'm not taking into account complex processes like Rayleigh Scattering (why the sky is blue), but for lower/less energetic frequencies of electromagnetic radiation, such as WiFi, things are typically less complicated.

The way that the data is encoded into the signal would also be undetectable to the human eye (were this in the visible). Imagine a light bulb blinking more than a thousand times per second; Alternating current is around sixty times per second, and that's not even perceived by most of us. Again, I'm simplifying things, but you get the idea.

My personal favorite is the first picture: We have a WiFi hotspot apparently between two stone pillars, or perhaps on the lawn behind them, moving away from us at relativistic speeds, with the fountain being so massive as to act like a gravitational lens.

OK, my soapbox has been sufficiently crushed.

Thank you. :)

Edit: Just wanted to say, yes, we live in a literal sea of EM radiation, some of it man-made, some of it natural... we can't see it, but our "human experience" of reality is incredibly limited.