Hi! On Common App, Brown has a section where you can upload your resume and ends with "some applicants maintain an online presence that showcases their background, talents, or creativity. If you maintain such a site, please feel free to enter the URL here:" I've had an art account on Instagram for all of high school to share my art with friends and family, would it hurt to link it?
Since you have had an interest in art and sharing it on Insta for years, it helps the applications committee connect the dots about who you are and what matters to you. Anything that gives them insight into your interests, passions, thought process is helpful in assisting them with determining if you are good fit for Brown and vice versa.
If I'm not mistaken there is also a place on the application where you can upload a video of yourself. I forgot what the prompt is but I think you have 2 minutes to record something interesting about yourself.
Good luck with applying to Brown.
To keep this community safe and supportive:
Hi!
If you feel that it represents your artistic ability truthfully, go for it!