A trickle of new retailers that keep late hours, like Beautiful World Syndicate Records and the 20th Century Cool vintage décor store, adds fun to the after-dinner stroll. (Not to be missed: 20th Century Cool's glowing display of uranium-spiked Depression Glass and its sublime collection of Roseville art pottery.)

What isn't so clear to residents, retailers, and visitors is what's going on in the gigantic mural in the middle of the block, which appears to depict a World War II-era submariner using a periscope to spy on actor Robin Williams. Curiously, Williams is holding a rosary.

Kathryn Ott Lovell, a spokeswoman for the Philadelphia Mural Arts Program, acknowledges that the surreal wall art, copied from a painting called "The Pathology of Devotion by Vincent Desiderio," is one of the more thought-provoking murals around. The artist's intent, she said, is to represent the intersection of science and religion. The guy on the right is not Robin Williams in a puffy shirt but a priest hearing confession.

While the mural has its fans - "There are people here who understand what it means and love it," said RoseLena's owner Al Masino - it's slated for a paint-over soon. A new, even bigger mural paying homage to the 125-year history of the East Passyunk retail corridor is on the drawing board as a replacement.

So on to the next mystery: What's up with the East Passyunk parking meter hours, which extend until 9 p.m. on Wednesday and Friday, if you bother to read the fine print? Shopkeepers say the schedule is notorious for surprising after-dinner strollers with a nightcap from the Philadelphia Parking Authority. *