in WP there is a setting where you choose, what is displayed when the visitor is surfing just to your domain without any special document given.
( like http://surniaulula.com , right?)
its the first in "Reading"
If you choose "latest Posts" index.php shows just a blog - but the Url in browseradresswindow is still your main adress.
A link like http://surniaulula.com is of course the link you want to be promoted most. Its the index, right? so if someone is doing a like to this adress you want this like on facebook to appear as company, website or blog or whatever - but not as an article, which can be changed every second.
so if index.php is liked, (whatever it shows) there should appear the description of index and the picture of your company on facebook not the description of an article, changing every day.
and you promised to do that with the "default picture" in the settings right?
just my 2 cents