Edited close up picture of Lord Ganapathi.
This is a photo of Lord Ganapathi standing as he was at the time of Ravana banging him on his head.
He is standing away facing west at a distance of thirty five feet from Atmalinga and his mother Goddess Parvathi is standing.
Lord Ganapathi was feeling shy of having made the Atmalinga out of it's shape by Ravana because he kept it on the ground asked his father Lord Shiva to pardon him.
He fell on his stomach at the Atmalinga saying so and prayed in several ways.
Lord Shiva having seen everything praised Lord Ganapathi for his intelligent efforts in planing to see that the Atmalinga doesn't reach Lanka had done what pleased Lord Shiva granted a boon that henceforth all or any pooja if performed by anyone on earth or heaven must be done only after doing Lord Ganapathi's pooja if not no pooja would have any effect over anything.
Thus any pooja performed from that day anywhere is done only after the pooja performed to Lord Ganapathi.