If you use [gallery] shortcode without setting the columns value, the default is set to 3. Some WordPress theme can either fit 3 or more column per row or less.
Imagine if you use [gallery] shortcode with default options regularly within your posts, you switch to a new theme and the theme could only fit gallery with 2 columns per row.
To overcome this issue, the plugin will force and overwrite the current number of gallery columns within any post that uses [gallery] shortcode with a new number of columns of your choice without altering or tampering its original options. It also includes feature to exclude post from being overwritten by this plugin and removing the default inline styles printed when the [gallery] shortcode is used.
For more information, check out zeo.my.