There are three “rose” windows in Blessed Sacrament Church. Each of the rose windows are virtually identical except for the centre. The main rose window (east) symbolizes Christ in the Eucharist. Mary is depicted symbolically in the rose window north.
This south rose window has symbol of a lily probably referencing Saint Jospeh, the spouse of Mary given that it is opposite the “Mary rose window.” While the lily often references the Resurrection of the Lord, also it sometimes references St. Joseph, symbolizing his purity and his chaste, faithful role as the guardian of Mary.