The circuit on top just connects a switch to a LED component,
but there are a few 'delay-nodes' inserted into the wire
to demonstrate a wire-delay.
You can toggle the input switches before the previous value
has reached the target gate, an effect that is similar to
the real traveling waves in the physical modelling
of a transmission line.
(Note: due to its simulation algorithm, Hades cannot really model
wire-delays. The small delay-nodes are actually just standard
simulation components, each of which uses the gate-delay model.
Still, you should get the idea of electrical waves traveling
along the signal wire as the source of delay).