'Altogether, the accounts of the apparitions provided the following details. Virgin Mary, her husband St. Joseph, and St. John the Evangelist appeared at the south gable end of the local small parish church, the Church of St. John the Baptist. Behind them and a little to the left of St. John was a plain altar. On the altar was a cross and a lamb (a traditional image of Jesus, as reflected in the religious phrase The Lamb of God) with adoring angels." (source)
Sometimes in prayer, especially during the Agnus Dei at mass, I like to go "in spirit" before the apparition of Jesus as He appeared in Knock Ireland. The Lord, our God, the Almighty and most Holy One, emptied Himself and appeared as a tiny lamb upon His altar of sacrifice.