When the gallery has been launched and you are logged into WordPress, the close button is no longer visible, because the admin button covers it. My client noticed this and it was pretty embarrassing. it’s an easy fix, using jquery, you can just adjust the top position in css by 28px when the admin bar is present. I will be hacking it for now in my local copy, but please let us know when you have a patch for this or if there is a setting or something I’m unaware of. But I have authored many plugins and have 20 yrs of full stack programming experience. And my guess is this went unnoticed, because you have to have large enough images on a small enough monitor to see it.