Every design has a primary entanglement with the form/function discussion. Put succinctly: type is what something looks like, while operate is what It does. Design tends to create efficient products look good: but creating something look stunning or new can sometimes damage its capability to do its job.
The entanglement, and the debate, is as follows. Where consumers wish for form as well as function, it may actually be OK to sacrifice some elements of functionality for a better look. It may also be the case that sacrificing some elements of the traditional functionality of a specific class of item may lead to new functional avenues being opened up.
This debate is very neatly captured by the history of the MacBook Air, by the way. Mac designed something that looked beautiful, but could no longer be used as a laptop because the ultra-thin case meant the device heated up quickly and burned people’s knees. On the other hand, the lost weight made the Air super light.
In terms of furniture design, there are certain functional boundaries that cannot be crossed. A sofa, for example, is defined as a sofa by its ability to properly support more than one seated human body. Therefore, any sofa that cannot do this is no longer a sofa but something else.
The look of a sofa, though, is important to its user. The look of a bed is important. The look of a wardrobe is important. Where possible. the furniture owner likes to have things that he or she believes to be beautiful, as well as knowing to be useful. In other words – he or she likes own stuff that has a form he or she approves of, without impairment of its proper function as a furniture item.
Designer furniture is not like (for example) designer clothes. On the catwalk, designers get away with showcasing outfits that are clearly impractical for use as actual clothes – enormous overbalancing hats or shoes so tall it would be lethal to walk in them for more than a couple of minutes.
There is, though, no catwalk for sofas or chairs. People almost always buy their furniture to use – and because of this, the designer is never really allowed to stray far from the fold. A sofa always looks and acts like a sofa. A chair is always capable of supporting a person in comfort.
Style and comfort are not the same things, of course – but then (catwalk aside) most jackets are jackets, whether they have massive 80s shoulder pads and cinch hips, or a 90s sag, or a more modern tailored look. In other words, they all do the job of a jacket no matter what they make their wearer look like. By the same token, most designer furnishing support people who are sitting on them, or allow people to sleep on them, or store things on and in them, despite their looks.
It is because of this that designer items often have two distinct looks – the overall shape of a piece, and the actual fabric in which it is clothed.