I think that as we did not see any characters in a state of undress or in explicit scenes, then we can assume that the audience could exercise a considerable amount of imagination based on what they saw. For example, the phantom saw Aragorn's 'look' as a meaningful glance at Eowyn, while I saw it more as concern. I wonder if this was the intention of PJ; if so, then it was a good decision. This allowed both for those who wanted to see dramatic romantic tensions and for those who wanted to see the high romance.
I agree with Bethberry that a lot of symbolism was used in the films, or if not symbolism, then other signs that we might or might not read into. Arwen being dressed in a floaty garment can easily be read as she was in her nightwear or that she was simply wearing a nice floaty frock, depending on the viewer. But nowhere was explicit imagery used - and what a relief because these days it seems a film cannot be made without an obligatory sex scene.
Looking at older literature, much was indeed made of a simple look or a touch, and in many cases this is far more evocative than any explicit scene. Much is made of the function of clothing and other objects in attraction; a woman can be clothed head to toe yet still wear clothing intended to attract or suggest what is hidden, such as corsetry, heels, earrings and so forth. I think examples such as this show that explicit scenes and/or nudity do
not always have to be used to show attraction between two people, a subtle look can indeed do just that.
So, I think the scenes with Arwen/Aragorn/Eowyn are actually subtly drawn and can suggest whatever we want to see in them. It's
fascinating reading what everyone
does see in them though!