Gavia has red nanobot eyes, and Malice did too whilst (presumably) her nanos were activated before she gave up the fight and went back to her usual green eyes.
I am vaguely assuming - and I very much wish to avoid being a Predictasaurus rex type poster here, imposing my tedious headcanon / assumptions / predictions upon others, so please take this with all of the salt grains - that when humans have their nanos engaged in duties such as protection, floating, etc., that this is indicated by red colouration to their eyes. And yup, Alice is different in this regard, as Sedna confirmed some differences between the two despite common vintage without further elaboration or explanation. Similarly whilst Ardent is obviously an adjusted human, the changes made were perhaps genomic or otherwise biological & irreversible (as Sitnspin said) without ongoing nano management, hence no red eyes.
Anyway, the dreamtime Loon bird too had red eyes characteristic of Gavia, and I love that the bird itself is of genus Gavia too. Seems a strong and pointed link to me. By contrast the Nightwalker has no colour to its eye holes at all. On that note I have thought it strange that it assumes anthropomorphic form.
I am curious to see what comes of the whale dreamtime prediction that we have now seen for the second time. I wonder what he / she / it represents?