[hnisoss]

The interaction of EM waves and their behavior is a long and complex topic to address here, however, keep in mind that the signal is sent out into void - what happens after emitting does not concern the emitter. Think of it as rain falling down, or water from the sprinkler. If you catch the droplets you ll cast a "shadow". Completely surrounding the emitter might create "Faraday" cage of sorts. However in reality in the droplet analogy, the EM waves curve around the buckets and leave the shadow. The reception of EM waves is a wave-cancellation process, but thats a deep rabbit hole..