Ok let me attack this from another direction. The scroll in a display is a fucrum, a piviot point. It helps nudge the viewer into a direction the artist wants you to go. It may depict a season, it may depict a time of day. It may depict a subtle change of contrast to a mood.
The scroll is usualy incomplete. For instance the scrolls of waterfall I have shown three different time within this post are vague.
There is no sky.
There is no stopping point for the water.
There is no pool.
Scrolls are meant to be left to the imagination of the viewer. In Ted Matson case he wanted to depict a grove of trees at the base of a tall falls, the pool may be hidden by a larger stand of trees you can't even see. Why, because it was not needed. You are meant to imagine what is surrounding this imagery. The waterfall does not need a pool. It is depicted by the grove of trees planted on a stone. Ted has told us that the trees are grounded.
The simple truth is in the display shown here by me, the scroll is shown where it is because that is as tall as my backdrop is. I wished to include the whole scroll in the photo. I could have moved the scroll up but then I would have chopped it out. I didn't feel it necessary to cut the image to get it perfect. If I were to use this display in a venue that afforded me more height, I probably would have shown it higher.
What if my tree is a tree growing on a ledge near the waterfall as it plunges on further in the canyon? The truth is it is left to the viewer to get from the diplay what they feel. If in this case you feel that the spray is what is benifitting the growth of the juniper..so be it. It's all subjective and though there are rules, there are really no rules. As shown with Teds piece, although everyone had something to say about the scroll being so high it did not matter, what mattered was that he captured something very special that was very simple yet very deep. Ted made you think....if you took the time to do it.
My real intent was to just show a nice picture of a tree a waterfall and a accent plant and make it look somewhat cohesive in a small amount of room.