Only the photographs on the mantelpiece really showed how much time had passed. Ten years ago, there had been lots of pictures of what looked like a large pink beach ball wearing different-colored bonnets -- but Dudley Dursley was no longer a baby, and now the photographs showed a large blond boy riding his first bicycle, on a carousel at the fair, playing a computer game with his father, being hugged and kissed by his mother. The room held no sign at all that another boy lived in the house, too.
This is from the book Harry Potter. Couple of things I don't understand:
How come Ten years ago can work with past perfect tense? As I know, 'ago' denotes simple past tense.
Is "what looked like a large pink beach ball" referring to Dudley Dursley? I can't image one could look like a large pink beach ball at all!