This picture may be of a liquid on Mars - because the reflections

I saw no reflections, I am not even sure where you are trying to point to. (provide and arrow)

of the creeks

creeks?!

are almost perfectly mirror imaged in the water

water?

below, which takes coincidence a little far.

I think you are taking assumptions to far.

Note that darker parts of the hill above are refelcted darker in the lake below. This would not occur as a shadow effect - only from a reflection. This
may be an illusion, but it is very doubtful. I think it is the real thing. You will need a very convincing argument otherwise to convince me - and I am a
skeptic.

If you were a skeptic you would not already be convinced the other way. You would wait for experts to weigh in.

put thing on the table too, if you think you know what the liquid is, say it.

-Justin Kelly