Typography is usually carefully crafted and constructed. It is the architecture of the 2-Dimensional world. Usually when we think of architecture we think of buildings or houses. Typography or letter forms house ideas, they are the bridge of communication. Some ideas like some bridges are more fancy than others. A way of making things fancier or more "ornate" is to add ornamentation. This is done through lines or shapes.
Even organic creatures can be made ornate or decorative. Not all decorative art has ornamentation, but the elaborate line work of Si Scott seems to be his signature style.
You can even make whole letters or phrases decorative.
You should try drawing the Sea Horse for extra credit.