A few more things I noticed about these photos...

One was the lack of a kilt belt with many of the daywear outfits.

But the first thing I noticed -- and I see the same thing whenever I see photos from this era of any kind of Highland Gathering -- was despite the fact that this was during the day and outdoors, every gentleman present was in a jacket and tie, if not a jacket, waistcoat and tie. Contrast this to the usual attire seen at Highland Games and other outdoor Scottish gatherings (at least here in the states); a t-shirt, or a "ghillie" shirt (which are also conspicuous by their absense in these older photos).