Headcanon: Murderbot's inability to control its expressions applies just as much to its feed presence as its face.
Like, we know emotions bleed through into the feed. I think MB's feed presence is extremely emotional in a way it can't control and isn't really aware of. That's why bots trust it so easily: it's feed presence is extremely honest and expressive, and they can tell that it doesn't want to hurt them.
Miki doesn't trust MB because of naivety, it trusts it because it's actually seeing way more of MB than MB is aware of; and regardless of any other incongruities, it can tell that MB means no harm, will not hurt its humans, and will protect them if it can.
