How about the way that they are all growing on the ridges of these dunes? As artful looking as the color version is, look at the black and white, doesn't it make it look biological? Nothing in geology could explain sand dunes like these. Unless you buy into the NASA streaks on the ground theory. I see what you mean about the shadows, I wondered that right away too. I think some of the tampering we see could be the covering of these shadows. I wish we could find other pictures of this area from MGS, MRO, Odyssey, Mars Express, or maybe we could find it on Google Mars, so far these are the only ones I know of.
I will post 1 example of each, shadows and hidden structures. They are not apparent and the structures have been "artfully" hidden.
First It is my opinion that upside down is rightside up pertaining to the original pic. This crop shows several shadows over the brim of the hill that seem too coincidental with the very tops of the black "trees". This, if true would negate my arguement that all of the "trees" are "art". There also seems to be some kind of white "bony" structure behind the trees.
In this pic there are no shadows I can see but there is a large white/colored rounded structure with a dark ramp that is a different shade from the trees sticking out at an angle from what could be an opening in the structure. Also there is a red colored structure that has been very blurred but you can barely make out a round opening on the left top side of it.
There is a lot more in this pic but my interpretation of what it is would not fly here.
Turning the contrast way down gives a greater perspective and detail, it also shows the base of our objects have structure, also notice the dust/steam/smoke/pollen cloud just left of centre and above the central objects (or below in Qs case), there also seems to be some side by side indentations in places.
There is no doubt the image has been filtered/edited to reduce detail, but I still cannot see the hidden structures or shadows.
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"Creating a fiction when stating a fact destroys the credibility of the truth one are trying to convey"
My own personal opinion is that the black was put into the picture to distract from and hide what is really in there, which are very large life forms or structures. Some of these black "trees" or flows as nasa calls them have shadows and some do not. This throws up a big flag (to me) I do see what appears to be faded out structures but that could be just optical illusion. The terrain does not make sense in certain areas. It looks like its overlapping itself.
I dont think that my way of clarifying a pic would add anything to this as I can also see the standard masking obfuscation over much of the pic.
Just to be awkward, I downloaded the image and turned it around to get a different view. What if these were roots (or red weed, as in War of the Worlds) and they were growing downwards towards the ground rather than growing up like trees? I have seen creepers growing like this and I just wondered if they were used to camoflage an area. The light green/aquamarine colour behind some of them seems to me to have structures in there. So, what it this is weed growing over a glass tunnel set into an escarpment?
Just speculation of course.