Has anyone managed to create rules with gallery has image?

I have a site soon to have many node galleries. I am building a editorial and publishing workflow, with the help of the Rules and Workflow modules.

When I came to add the condition to the rule "gallery content has image", I became a little stuck. No such thing seems to exist...

So I wondered if anyone has found a way, as I can't seem to find the answers I'm looking for anywhere...

Any pointers would be much appreciated...

Guy