Oh man.. Please do! I would love to see some shots with accurate handling of the swords.
All right, I finally managed to take some pictures, so here they come along with an explanation. Although there are many different ways and styles of fighting with swords, with kendo being only one of them, it is safe to assume that the grip handling of two-handed swords is quite universal. You'll see why as I go along with the explanation.
The right hand holds the grip right underneath the cross-gaurd, while the left hand holds grip at the very bottom (in some cases the pink doesn't even completely cover the grip). The ideal length between the two hands is one fist, although it isn't possible for the guy who poses in these pictures to do as the grip is too short for him.
I'm not sure if the term I'm going to use here will be correct (after all English isn't my native language), but the meaning behind this grip is that it allows the user to produce a 'lever-effect': the right hand guides the direction of the sword, while the left hand tilts the sword. This enables you to swing the sword
MUCH faster than one who doesn't know how to handle swords would. Also, from my experience, swinging the sword the 'right' way will result in the typical "swoosh" sound that is characteristic to this weapon; if you don't use the 'lever-effect' technique, you will hear nothing at all.
So, as you can see, holding a sword correctly isn't about show, it is only logical to wield it that way. Also, you may want to keep your wrists stretched out, like it is shown on the pictures, otherwise, if you keep them bent like the model in some of your photos does, it's sure fire to have them seriously injured during fights considering how hard fighters hit each other with these weapons.
I'm not going into stances, because unlike the grip, I'm very sure that these aren't universal. So all I can say about that is that you can exercise some artistic freedom with that
Hope this helps!