When you want Content Authors to be able to upload photos without your approval
Make sure the checkbox in the "User Image Options" section is unchecked. You get there by going to Administration > Sites > Blank Client Site (or site name if one appears here) > Settings then scrolling down to find "User Image Options" and unchecking the check box.
Once done there, you need to make sure that the Role for the user in question has the same permissions. Go to Users & Security > Task Groups > then open the Role with (site tasks) next to it. When the next window opens, scroll down to the bottom of the screen and look for "Profile Security". Under this section check the box next to "Approve photo rights" and save.
This will give you a checkbox in the image upload screen that says "Approve". This box is checked by default and will allow your users to approve their own photos.