Tintin Eurosignal commercial

This was published as a commercial for the Eurosignal phone system in 1977. It was published in Metal Hurlant 63 and presented in the French Tintin magazine in 1979 (No. 212N). It is also published and presented in Goddin´s Hergé Chronologie Vol. 7, p.382-383. I would have guessed this is mainly Bob de Moor, with some involvement by Hergé himself. But in the Tintin 212N article it is explicitely presented as a piece created by Hergé (as opposed to a Studio piece presented in the same article), and pure Hergé is the impression one gets from reading Goddin as well.
Anyway, quite an interesting piece for Tintin fans, I think.