Nice colors. Suggest cropping the top to have as much space above the flowers as below the vase. I would also leave out the dado rail which does not contribute. I would intensify light and shadow a bit. Try not to have the vase dead centre, perhaps a small metal object beside the vase?
Dip in hair gel and shape bristles with your fingers. Should later dissolve in brush dip. If this is meant to be a filbert I would reshape the bristles with a razor. If the brush is a round, then the gel will do the trick.
Alternately, a coat of brush dip and an elastic band may bring them back into line.