The "add to" will make you character viewable by others. In the character bar below you can click on Ayy and see her character sheet (as I've added her to the library), but if you click on Zaoanlu you'll get a character not found. Personal preference whether you add it or not - the GM will always be able to see a character sheet in their games.
You can post as your character once the character has been accepted by the GM. You'll have a "Post As:" option above the post dialog when that happens.