Religious art has a different significance than with secularist or Protestant teachings. Catholicism embraces the concept that religious art, whether sculpture or paintings, is a tool that both focuses the mind and effectively offers a window or portal for our minds into heaven. They are no more important than a pane of glass through which we are looking. Bowing simply shows proper respect and deference. The traditions of bowing, kneeling, or prostrating arose from the postures and gestures of respect demanded by royalty. The Church taught that if we displayed those postures and gestures to humans and human symbols like flags, how much more deserving should symbols of God be.
It should be noted that Protestants often display their own gestures and traditions of respect. I have seen Protestants brought to tears by locations in the Holy land. I have seen Protestants show similar respect to the Bible both in attitude and in their insistence that the "B" in Bible be capitalized. I have even seen some bow to and kiss the Bible (As is done in the Catholic Mass). In the end our differences are more cultural than than theological. We both love the same God.
Peace be with you
You won't see me kissing the bible simply because I know where it's been. As for treating it with respect, well, I'm guilty of that but only because it cost me $79.95.