Philosopher Kwame Anthony Appiah draws a distinction between the “pretty” and the “beautiful”:

I think Kant was right in that beauty is a word that belongs to sensation. It has to strike the senses, whether it’s the ear or the eye. And I think he was right in that it’s connected to pleasure in the sensory experience and the desire to return to the experience. But what is merely pleasurable is pretty. Beauty has an element of that thing that makes you want to come back, that engages you cognitively. It’s this combination of the power to attract the senses and then its being rewarding to think about the experience that you’re having that makes for real beauty.