Is this dress too short for a wedding?

 

The friend of a wedding guest took to Facebook to detail her pal's agony at a wedding and all over a dress.. (the one pictured above) She wrote:

"She says she got treated rudely by other women at the wedding who saw her as a target for wearing this dress. A woman came up behind her and slapped her on the bum and said it was on a dare from a group of other women who were watching and snickering.
"Someone else seemingly purposely spilt a beer on her. "She's amazed that grown women could be so immature and such bullies. "But wait. She wants to know - did she bring ANY of this on herself by wearing this dress to a wedding?"

Some commenters think she stole the couple's shine while others think the dress would have been appropriate anywhere else but not a wedding. Thoughts?