You can post several layouts in a gallery upload: when you click on the button to select your photos, you can chose more than 1 picture. Add your description (the category, title and description apply to all layouts, but you will be able to change them individually in the next step). And then hit the "upload/submit" button.
In the next screen, you can see all your layouts : you can edit each title and description if needed. Once you're done, just hit the upload button.
Hope it helped!