I would say "comprises" in the active voice means "encompasses". X not just contains Y, but X is made up of Y. When X comprises Y, then Y constitutes X. Or to

I would say "comprises" in the active voice means "encompasses". X not just contains Y, but X is made up of Y. When X comprises Y, then Y constitutes X. Or to use passive: X is made up of Y, X is comprised of Y. Y are encompassed by X. "Is comprised of" is a totally cromulent use and I would claim it is more logical and more easily understood than the "X comprises Y" usage.