I am totally confused after reading all the suggestions! 😕
My thought is, that if there are picture on the CD then they must have been taken maybe when a photographer was in the house. Could it be that Urshi contacted the photographer that was used during Kinjal and Dhaval's marriage. Urshi may have suspected something was not right on that day because she did bump into Kinjal when she was on her was out (Kinjal's face was hidden and Urshi gave her a coin, I think. Maybe the photographer took by accident pictures of Kinjal running away. Urmi may spot this in the picture and these are what are on the CD. So this would embarrass the Modi's that their daughter was running away on her wedding day. To stop this from becoming common knowledge the Modi's may be blackmailed to take Rashi back.