At the moment (1.4.7) you are able to change the images per page and the sort order. In my opinion it would be helpful to have a filter e.g. show only unpublished images.

Lots of things would be useful ;-) But seriously try the publishContent utility plugin which gives you a far more convenient overview about all un-/published items from the whole site (incl. Zenpage items and albums). Otherwise feel free to open a feature suggestion ticket.

OK tried the plugin. However that's not what I would need :-D. I do not set pictures to published unless finished editing like adding description and tags. To find the not yet finished within the image editing part of the admin my suggestet filter would be a very nice to have :-P
Feature suggestions are in GitHub?

You can go from there to edit an image as well ;-)

Yes, feature suggestions are on GitHub. Seems this makes sense since we have similar for at least Zenpage articles. Might not get into the 1.4.x releases though.