Ron's reflection/Sorting order

[Barb]

Cindy:
Also, maybe the reason we don't see Ron's reflection in the mirror 
is an aging problem.  He would have to be 17 to be head boy/Quiddich 
captain, etc., and they couldn't do that credibly for the film.

Actually, they have excellent morphing software for this now.  When 
children have been missing for a number of years and the authorities 
still want people to be looking for them, they can age photos taken 
at an earlier age and make a child who disappeared at age 8 look 
15.  I think they didn't show Ron because Harry never saw Ron, and 
this is still mostly his PoV.

Heidi:
One terrifying thought did cross my mind- what if they did the 
sorting in birth date order? It would give credence to that misery-
inducing 1979 argument for Hermione's birthday as she was sorted 
first. But there can't be that many students younger than Harry. So 
maybe not.

This thought doesn't terrify me, but it's extremely unlikely that 
Harry is among the five oldest students, especially with a July 31 
birthday.  This was clearly just for cinematic expedience.  
(Although the revelation that Susan Bones is a Columbus is somewhat 
irksome.)

A few people mentioned Filch being in the Slytherin stands.  He has 
to sit somewhere, and for that matter, Quirrell was sitting just a 
bit behind Snape (who was never clearly established as head of 
Slytherin House).

--Barb