I just realized that after doing a custom google search on my photo gallery the search results looked somewhat like this:

Best hiking photos. 1. Great North… … 78. Sunset in… 79. Walking in … 80
. Walking in … 81. Walking in … 82. Blue Tounge… 83. Flinders. …
www.allgreatwalks.com/photos/main.php?g2_itemId=267 – 18k – Cached – Similar pages

Extremely annoying.

By default Gallery2 does not seem to add any meta tags to its generated page headers, so google just displays some jibberish about some link fragments found within the document.

In order to fix that you’ll have to add some description and keyword meta tags to your pages.

Unfortunately there is no real convenient way to fix it, it only works after editing the theme.tpl file by hand.
Here is a link on how to do it:

http://chumby.net/2007/03/27/adding-meta-tags-to-gallery2/

In this article the author describes how to edit
gallery2/themes/matrix/templates/template.tpl

But actually it is
gallery2/themes/matrix/templates/theme.tpl
that needs to be changed.

Now Gallery 2 should automatically add your titles and descriptions to its meta tags.