Painting that Freaked Ali Out on PLL

Remember the painting Ali sees at the funeral house in “Surfing the Aftershocks” PLL 5x03?  The painting is Arnold Bocklin’s “Isle of the Dead” referencing Val Lewton films.  Ali saw the painting and freaked out.  What’s up with this mystery painting?

"Isle of the Dead" pic.twitter.com/gdfHOLZumS
— Joseph Dougherty (@Kockenlocker) August 3, 2014

This isn’t the first time the painting has appeared on “Pretty Little Liars”.  It also showed up in “Stolen Kisses” PLL 3x08 in the background when Ezra’s mom tries to bribe Aria into breaking up with Ezra at the museum. 

At the museum show in “Stolen Kisses.” If you look quick you can see it in “Grave New World” in the Collins house. pic.twitter.com/N0kioLq55S
— Joseph Dougherty (@Kockenlocker) August 3, 2014

The painting also could be seen in the Collins house (when the Liars visited Ravenswood) in “Grave New World” PLL 4x13.

Joseph Dougherty, writer/producer/director on PLL, says we will understand why the painting made Ali nervous, if we pay attention to future PLL episodes.

He gives us the hint that "it has to do with a memory". 

Anyone have theories on why this “Isle of the Dead” painting is so significant on “Pretty Little Liars”?