Hello Ben,

A "splash" page, unless customized otherwise, is coded to link that large button to the page set as a homepage. Here is a post that describes splash pages more in detail: http://nationbuilder.com/how_do_i_set_up_a_splash_page

An important thing to note is that in NationBuilder, "splash" pages are ones that have been set to "splash page" in the settings, and have a small water drop icon to indicate their function. When a page has this setting, the splash.html file, located under Websites > Theme > splash.html; controls the look of the page.

If you'd like us to look at this further, please provide a link to the splash page. 

Thanks.