The Romans conquered many lands and usually when they did they let the conquered land keep their own culture. When they conquered Greece they found that they really liked many aspects of Greek art and culture.
The Romans really liked Greek sculpture. Romans sculptures are amazing but the Romans built upon Greek sculpture. The Romans made sculptures more detailed and they could make more of them, quicker.
They also adopted some of the principles from Greek theater. The Greeks focused on more classical themes showcased in arenas while the Romans held theater events in arenas as well but showcased gladiator games and executions.