Essentially: If someone is lovely, you want to sit back in your comfy chair and have a nice meal or drink while you chat with them. You'll have a lovely time. If someone is cute, you want to grab ahold of them and hug and cuddle them because they are irresistibly adorable, be it animal, child (your own or not) or your significant other. It's called cutesy. Or adorableness. Or adorability. Or kawaii. I don't really know how to explain it any better, except to add that when they encounter something cute, people tend to sort of act cute themselves; bringing their shoulders and heads closer together, tilting their heads, looking slightly upwards and acting as if they want to, or even are, hugging something because it is irresistibly precious in an innately human way that only something human(oid) can instil in us.