I only used that term because it sort of rhymed with "dust'. I think it more probable that these putative lifeforms would be more functionally similar to algae or chemotrophic bacteria. You yourself frequently point out the vast differences in Mars, so why couldn't Mars "bacillus" be a thousand, or a million times larger than Earthly ones?

My point is that this distribution of the darker particles on the vertical surfaces has more resemblance to a bacterial culture from an agar plate than it does to a semi-random distribution of dust, though of course some dust is present. No doubt there are also alternative explanations as well, such as that these are embedded sedimentary particles, though the visible distribution looks even less likely for that.