The reason Rihanna was all dressed up in Gareth Pugh this week, was because she was headed to Allegra Versace’s 23rd birthday party at the Gramercy Park Hotel in New York.

Allegra wore a neon pink Versace Fall 2009 long-sleeved dress with a shimmering nude clutch, and nude suede heels.

You’ll notice that much like her mother’s Versace pieces Allegra dress is slightly modified.

The silver detail on the waist of the runway version is replaced with a pink satin panel.

Donatella obviously past down her wisdom of modifying pieces to her daughter, as the designer does this with every piece she wears.

In this case she has modified this stunning white zipper strapless Spring 2009 dress into a one-shoulder dress.  A tiny change yes, but one that makes her stand out from everyone else who owns this dress.

The designer completes her look with a pair of slate grey platform heels from her own Fall 2009 collection.

Credit: Style.com & Ant Griffith/bauergriffinonline.com