In the earliest posts on the Sacred Heart, we discussed what a marvelous and appealing visual image it is, having the love of God brought to the believer’s eyes. The DPPL seems to suggest we need new images, not just the old ones:
173. Popular piety tends to associate a devotion with its iconographic expression. This is a normal and positive phenomenon. Inconveniences can sometimes arise: iconographic expressions that no longer respond to the artistic taste of the people can sometimes lead to a diminished appreciation of the devotion’s object, independently of its theological basis and its historico-salvific content.
This can sometimes arise with devotion to the Sacred Heart: perhaps certain over sentimental images which are incapable of giving expression to the devotion’s robust theological content or which do not encourage the faithful to approach the mystery of the Sacred Heart of our Savior.
Is the theology a little more developed than the art?
Recent time have seen the development of images representing the Sacred Heart of Jesus at the moment of crucifixion which is the highest expression of the love of Christ. The Sacred Heart is Christ crucified, his side pierced by the lance, with blood and water flowing from it (cf, John 19, 34).
The Directory on Popular Piety and the Liturgy is online at the Vatican site.