When you see flowers in a rice paddy you can't help but use your fingers to draw them. Have you ever seen rice paddy flowers? They're beautiful. And if you can draw them you can capture that beauty and show it to everyone.
Even though you tried to draw the flowers as best you could, whenever someone looks at it they smell B.O. (びょう). Maybe it's because you were drawing for a really long time and kept sweating. Maybe it's because you are just a stinky person. But no one wants to look at your drawing for long because all they can smell is B.O.