cigars of the beeper:
Firstly, Professor Topolino has all of the shutters in his house closed up.
I would imagine that the absence of Boris the servant might be one reason: he closed them the evening before, was called away, and the Professor didn't have time or the inclination to open them all himself.
It is also good weather - perhaps the house is cooler if the shutters are kept closed?
cigars of the beeper:
Secondly, Inside Professor Topolino's house (page 23, panel 5) there is a small portrait of Dr. Müller hanging on the wall.
I'm not convinced by this personally: it's a picture of a bearded chap, certainly, but not Müller specifically - there are several similar figures in the books (just look at the gallery of portraits inside the covers of a hard-back album for some more), so I think it is just a typical look for Hergé to draw.
cigars of the beeper:
Is this not actually Müller, but instead a portrait of his servant, Boris?
I think the Professor would have to be very sentimental to have a portrait of his man-servant on display in his house so prominently.
cigars of the beeper:
there is a little old man standing next to a building in the region of the upper right-hand corner who looks surprisingly like Philipulus the Prophet.
That's a more plausible identification, but he's lost his trademark hair, and picked up a wife or girlfriend! Personally I think it looks more like a descendant of Geriatrix and the beautiful Mrs. Geriatrix from
Asterix!