How did the modern style of catwalk modelling evolve? Is there a particular rationale behind the walk, the 1000 yard stare, the total lack of emotion on display - is it meant to direct attention towards the clothes or is it the general result of 8cm heels, no food and too many drugs, or what?
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Just a total WAG but it’s about as close to being a mannequin and still moving as humanly possible
There’s probably a number of reasons, but I think one is that couture is bought to a significant extent by those who wish to appear “a cut above”. Smiling and looking friendly (which might usually be associated with performers before an audience) are features of trying to please. Ignoring the room and looking bored and haughty, as if you above it all and have nothing to prove, is probably the way some potential buyers would have their clothes make them.
Nah, groman has it. It’s all about the clothes. It may be fun to read other psychological factors into it - and probably impossible to separate them out entirely - but no matter what those are the basic model would come out the same because it’s all about the clothes.
I don’t know about the “strut”, but the first ever designer to use a catwalk was Lucy, Lady Duff-Gordon, aka “Lucille”.
She’s also famous for having been a Titanic survivor.
This may sound a bit snarky, but from what I’ve heard of the modeling community the answer usually is drugs. The total lack of emotion is actually a total use of concentration, so that super model A doesn’t fall off said catwalk. After all, they must consume something in order to live…it surely isn’t food. 
Hardee’s recently had a promotion that included giving favored customers a card to use for discounts. The card had a picture of a model holding a very large cheeseburger as if she was getting ready to chow down, she was dressed in overly sexy Western wear,and was seated on a mechanical bull. You could move the card and it would appear as if said model was actually riding said bull. I had 3 thoughts at seeing this card: