The "Pru" is the Prudential Center, a large skyscraper in Boston housing the offices of the Prudential Insurance Company as well as a huge urban mall. The building casts quite a shadow when the sun hits it right, so presumably that's where the title came from (hence the mentions to Boston).
To reply to Jotchy's question:
The "Pru" is the Prudential Center, a large skyscraper in Boston housing the offices of the Prudential Insurance Company as well as a huge urban mall. The building casts quite a shadow when the sun hits it right, so presumably that's where the title came from (hence the mentions to Boston).