Theme doesn't match between selection and preview

I select a theme but it doesn’t match what’s in the preview.
Here’s a screenshot using ‘Split’ as an example of what I’m talking about.
Is it that the theme displayed in the picker is one that’s been fully customized?

The image in the picker is just an image with the name preview_large.jpg (or .png) that is part of the contents of a theme.
RapidWeaver uses these files from all themes to show an example of the theme.
It’s up to the developer to add the image to his/her theme, so it’s not a ‘live’ preview, but an example of what the end-result could be.