Before revision:  In these problems, intermediaries compete through offering menus of multifaceted consumption bundles to agents, whereas the principal is limited to regulating sub-aspects of the sold bundles by legal , informational and administrative barriers.
After revision:  In these problems, intermediaries compete through offering menus of multifaceted consumption bundles to consumers with hidden tastes, whereas a manufacturer with a potentially different goal than retailers' can regulate only the sold goods but not the charged prices by legal barriers.