These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Chie does not recognize Rikuo's glasses as being glasses. Yet her guardian wears a pair.
Conversations in normal tones somehow don't carry past the intended recipient, even in a small space without any apparent soundproofing.
If androids really are intended to be just appliances, it would make little sense to equip them to eat, drink, blush and cry. The former two might be acceptable, if their services include cooking, but the latter are exclusively emotional expressions.
It is implied that no two robots look alike, which would be useful for quick recognition by their owners, but inefficient for mass production.
Moe: Sammy, very much so. Rikuo might also qualify, due to his woobie status.
Tear Jerker: Katoran's story and the last episode are the most significant ones. The movie implies that Nagi's backstory might be the worst of all.
The Woobie: Rikuo witnessed a robot playing the piano and was moved by it. He subsequently fell into a depression, because he was beginning to feel like his efforts were worthless.
Uncanny Valley: Human-like robots are a source of discomfort for society, given that they are similar in appearance to human beings but not of human origins and as such, are not expected to be regarded in the same manner as humans.
Woobie Species: Robots. The ones seen so far have been, if anything, more likeable than the humans (to be fair, only a small portion of the cast is indisputably human). And yet they're completely unable to express themselves, for fear of being hated and abandoned by their masters.