Because it's just a little bit boring to say that something's eldritch just because it looks odd or alien. Insect eyes have thousands of ommatidia. Squid are very much a terrestrial animal.
If it's a half-metaphor, though…
And it's play with identity, perception, points of view, deferring perception, deferring decisions, identity defined through others, 'nothing without an audience'. I love those things, because they're so blatantly achievable. Minds are deeper and weirder than they're portrayed, and metaphors anyway.
I mean, at the very least, plurality is a thing. So the always-singular stable 'obvious' model of identity and consciousness already doesn't work. And you could ask: what other spaces does this open up?
Fascinating, really.