Here are a few links to give context to the brief selection from Bell. I have excerpted a couple of passages that illumine Bell's key concept and its distinction from beauty.
"When I speak of significant form, I mean a combination of lines and colours (counting white and black as colours) that moves me aesthetically.
"By "significant form" I mean arrangements and combinations that move us in a particular way, . . . .
"To appreciate a work of art we need bring with us nothing but a sense of form and colour and a knowledge of three-dimensional space.
"#9. Some people may be surprised at my not having called this "beauty." Of course, to those who define beauty as "combinations of lines and colours that provoke aesthetic emotion," I willingly conceded the right of substituting their word for mine. But most of us, however strict we may be, are apt to apply the epithet "beautiful" to objects that do not provoke that peculiar emotion produced by works of art. Everyone, I suspect, has called a butterfly or a flower beautiful. Does anyone feel the same kind of emotion for a butterfly or a flower that he feels for a cathedral or a picture/ surely, it is not what I call an aesthetic emotion that most of us feel, generally, for natural beauty. I shall suggest, later, that some people may, occasionally, see in nature what we see in art, and feel for her an aesthetic emotion; but I am satisfied that, as a rule, most people feel a very different kind of emotion for birds and flowers and the wings of butterflies from that which they feel for pictures, pots, temples and statues. Why these beautiful things do not move us as works of art move us is another, and not an aesthetic, question."