On an emotional level, Bernini's sculptures were revolutionary for exploring a variety of extreme mental states, such as the anger seen here. David's face, frowning and biting his lower lip, is contorted in concentrated aggression. Baldinucci and Gian's son tells an anecdote of how Barberini would hold a mirror up to Bernini's face so the artist could model the sculpture on himself. This bears witness to Bernini's working methods, as well as to the close relationship he enjoyed with the future pope.