How to highlight locations that have an image attached?

Hi, first of all huge huge thanks to plugin author(s) – very lightweight and does exactly what we need. Glad to see it is supported on daily basis!

I have one question regarding the free version. We set up all the options and added two custom text fields and image upload. Is there any way we can distinguish locations that have either (preferably an image)? On the map they will show up same as all others, and if the user clicks on that location, a blank window pops up and nothing more.

Any smart way to do that?

Thank you!