Using CSS to hide H1 tags
 

Our designer used this popular code:

Which does exactly what you describe: push the "text" over by 9999 pixels so the h2 tag does NOT display on a regular browser (Only in the source code for search engines). The page shows a graphic but not the h2 tag.

However, if you use a text only browser, the h2 text tag will indeed display.

I also question if this is a safe technique from an SEO perspective since this in fact "hides" a tag from a user, but not from search engines.