I thought it fit quite well with the shadows and deer aspects of the Nara clan in general, which is why I submitted the post.
I don’t think it would have to be specifically a Shikasuke child, but I can see how it would add to the nightmare fuel that is Sakako “you better pray not to encounter her in the woods alone” Uchiha.
Is that moving shadow an actual shadow, a branch blown by the wind, or a scary-ass deer? Who knows?