Before a Zarestia Image Gallery is made, there was already a previous image posted on the page that got removed under the grounds that it was ambiguous whether or not the woman in the picture was Rem or Zarestia. If you have proof of the latter, or some other picture of Zarestia that isn't fanart, go for making the image gallery.
Also, I would make the page first before adding in the tabs in order to avoid having red links.
Mostly a rationale on how it can't be Rem in that scene and has to be Zarestia interacting with Rigel. You can add your reasons to the pre-existing thread down below the Zarestia page when Gracedharperd asked why the image was removed.
Well, the clothes match her description, and the picture is in the chapter section where Rigel and Zarestia are walking together and she begins to hum. Also, she has a lot shorter hair than Natsuki Rem.
But yes, I'll be adding these reasons to the comment section once I get the image ready for the gallery.