How to Put a Picture on the Desktop in OS X Mavericks
One of the ways OS X Mavericks allows you to customize your Mac is by choosing your Desktop’s background. You can choose any picture you like, for example a portrait of a dog.
Here’s how you can change your Desktop picture if you care to:
From the Desktop, choose app→System Preferences.
Or Control-click the Desktop and choose Change Desktop Background from the contextual menu, and skip to Step 3.
The System Preferences window appears.
Click the Desktop & Screen Saver icon.
When the Desktop & Screen Saver pane appears, click the Desktop tab if it’s not selected already,.
Click a folder in the column on the left and then click a picture in the area on the right.
In this case a picture called Elephant was clicked, one of the items in the Desktop Pictures folder.
You have at least three other ways to change your Desktop picture:
Choose the Pictures Folder in the list of folders on the left side of the Desktop & Screen Saver Preference pane and then choose a folder by using the standard Open File dialog. That folder then appears in the list; you can use any picture files it contains for your Desktop picture.
Click one of the iPhoto or Aperture items in the column on the left side of the Desktop & Screen Saver Preference pane.