You can use this page to test the Theme's handling of the shortcode, including the columns parameter, from 1 to 9 columns. Themes are only required to support the default setting (3 columns), so this page is entirely optional. One…
This is a test for Jetpack's Tiled Gallery. Install Jetpack to test. This is some text after the Tiled Gallery just to make sure that everything spaces nicely.
VideoPress, especially as a video post format, usually provides some unique styling issues. You will need to install Jetpack or Slim Jetpack plugin to turn the shortcode into a viewable video.