Yes, good to see some action here.
For the not unlikely case that the contrasts topic wins I'd explain it as a broad freedom (as I said above). Imagine the possibilities.
You could have, and that is likely, an elf-elf contrast. Since we all love Rayek (We do, don't we?!) e.g.
Rayek vs. Venka (brooding, temper vs. relaxed mood, calm, cool minded)
Rayek vs. Mender (sometimes similar in temper, but different in their appearance / phenotype)
Shenshen vs. Leetah (sisters, but still full of contrast)
Even Rayek early Sorrow's End time vs. Rayek later in the story gives a contrast.
But you could also see a human elf contrast, wolves, preservers. Mix in whatever comes to your mind.
Even landscapes of desert vs. deep green forests would be a contrast (one could merge this in a background).
Or have a collaboration with two different art styles.
I think it really offers vast freedom of choice.