Hey, the "free" galleries are only a selected few hi-res pictures that the producer has chosen to use to promote the scene. The actual gallery is in a zip file that you get when you buy the video.
Not all UMD scenes have video. When you view the download info page for any scene, it will lay out for you exactly what you get. It lists the files, tells you the file size, how long the video is and its bitrate, dimensions, etc. Or if it's just pictures, it tells you how many pictures are in the zip file.
MM
Stay messy, my friends.