From: Pittsburgh, PA
I did answer this in your email, but wanted to repost the info here for folks who might have the same question.
If it's a matter of swapping out your current jpgs for better quality ones, you can simply upload a different image to override your original.
As to deleting a whole slew of work, our delete feature isn't quite ready yet. In the interim, as Vicky suggested above, you can select the "hidden" option as each image's "image role" that you want to hide. We do plan to make the hidden feature work like a recycle bin in the future so you should be able to do a bulk delete of everything placed there that doesn't have a show, art of the day, or certificate of authenticity tied to it.
Get out of the vacuum and express yourself!