E-mail subject sent by skitch as conversations on Gmail

Since lots of people out there use Gmail, and it's "conversation" e-mail grouping is awesome, why not take advantage of this and use a consistent e-mail subject (this is what really matters when gmail tries to group messages, apart from sender) when sending notifications?
It would allow, for example, that the "modifications to a image" e-mails sent by Skitch become grouped (perhaps by image?).

Even for those who don't use Gmail, this makes easier to filter, for example.