Why does Hester become the center of the crowd’s attention? What irony does the narrator see in the scene?

The irony was found in the scarlet letter he had imprinted upon his skin. He wore the letter with shame, but he did so privately..... Hester wore her letter and suffered public shame, but she also healed..... Dimmesdale never had the chance.

"Dimmesdale stands on the scaffold calling Hester, who slowly comes over to him. Chillingworth bitterly tells Dimmesdale that there is no place on earth he could have escaped to, except on the scaffold, where he would have been safe. Hester is terrified that all three of them will die after this spectacle.

The crowd is bewildered by the actions of the minister. He tells them that he should have stood with Hester seven years earlier. Dimmesdale then indicates that he has secretly worn the badge of the scarlet letter the whole time, without anyone knowing it. At that, "he tore away the ministerial band from before his breast. It was revealed!"

Dimmesdale then sinks down to his knees and asks Pearl to kiss him now. She does, and "a spell was broken ... her tears fell upon her father's cheek, they were the pledge that she would grow up amid human joy and sorrow, nor forever do battle with the world. Towards her mother, too, Pearl's errand as a messenger of anguish was all fulfilled." Dimmesdale then dies on the scaffold."