The song 'Be What You See' by Paul McCartney conveys a message of self-reflection and authenticity. It encourages listeners to embrace their true selves and not to be swayed by external pressures or expectations. Key themes include self-acceptance, inner peace, and the importance of maintaining one's individuality. One poignant aspect of the song is its minimalist approach, which underscores the simplicity and purity of its message. McCartney uses subtle and soothing melodies to complement the lyrics, creating an introspective experience for the listener.