Caring and informality are its hallmarks. If a service starts 10 minutes late, that's okay. Everyone knows the names of all other group members. There's almost enough people to fulfill basic needs in the areas of finances, programming, and personnel. Caring is still a distinguishing characteristic, but it doesn't happen quite as often or as spontaneously.
Services are a bit more formal.
Providing care and services to members must now be organized, or it won't happen. The church hires or yearns to hire a parttime staff member to help facilitate ministries which volunteers performed without pay when attendance was less. That's why each needs a somewhat different pastoral leadership style. The style that works in one phase of a church's development will not be effective or feasible during another phase. The first style sees the pastor functioning primarily as a shepherd.