I think that when people refer to how she "looks" they aren't simply receding to her physical appearance in isolation. Its more to do with her demeanor and how she presents herself. Traci Andrews wasnt too taxing on the eyes but she was clearly a lunatic.
LL's photos are taken in ordinary social situations which are entirely normal for a woman of her age. She clearly has friends who think enough of her to take those photos and post them on social media. I don't recall seeing similar photos of any serial killer ever. Indeed, when it comes out they almost all seem to be weird loners with very few friends - usually because people dont want to be associated with them. The likes of Ted Bundy may have presented as charming to his victims and potential victims but that was never something he had to keep up for any length of time.
Adding to this - from the released photos she seems modest, educated, slightly shy, middle class, “normal”. Of course appearances can be deceiving, and of course none of these factors preclude somebody from being a murderer, even if accurately surmised.
But the human brain is programmed to seek patterns and create quick assumptions based on that. It makes perfect sense that most people would look at her and think “I’m safe, she’s not a threat”. It’s just evolutionary shorthand to save us starting from scratch assessing every new encounter - and anyone who pretends to be immune or above such biases is not being entirely honest, or is a robot.
My money here (if she is indeed found guilty) is still on an “angel of mercy” type situation. Most people have no idea the agonised suffering that pre-term babies can endure in hospital, and often we work so hard to preserve life in these babies only for them to go on and live short, difficult and painful lives with disability and further hardship throughout.
NOT saying that justifies anything, or that any of those lives are less valuable or important - personally, I think it’s all the more reason to show them love and compassion.
But I can certainly imagine a relatively informed, educated but pathologically detached viewpoint where somebody begins to think they’re better off “out of their misery”, so to speak.