the "Download & Extend" page's themes thumbnail has this url drupal.org/project/project_theme;
and there are only 14 themes showned.

and for example, Acquia Marina theme is in drupal.org/project/acquia_marina

Comments

If you are trying to report an issue with the drupal.org website you need to use the issue queue not a forum post.

ok, sorry and thank you

CC