how is the picture on page 13 (middle) both symbolic and ironic?

The picture on Page 13 of the novel compares Marx to God. In this comparison, we need to remember how young Marjane is. She's young and impressionable, she's also vulnerable to the thoughts and opinions of those around her. This picture is not symbolic of communism, but rather what Marjane believes it has in common with she identifies with God. Thus, she is captivated by the promise of love, equality, and peace.... not the communist regime.