This is very much a stock-standard wiring diagram-system. The left
window is a scrollable window of buttons, each of which correspond to
some unitary operation on some number of bits. Well, kind of. The
yellow-backgrounded "observation" operation isn't exactly unitary in
any useful sense. And the Is-it-an-integer operation (2nd complete
row from the top, far right-hand end) is only unitary if one imagines
that one also has an infinite supply of monads in the hilbert
space.
The right hand window is of course one of the editting windows
illustrating the general style. Challenge question for the bored :
given that T is the standard Toffoli gate - in permutation notation it
is ([110][111]) - what is the distribution of observations as produced
by the measurement at the bottom?