You can now add an image to the address labels. To do this, tap the Settings button at the top-right of the preview page, and then make sure the Include Image on Label switch is ON.
Then Tap on Select Label Image cell to choose the image.
If you would prefer to not have an image on the labels, just make sure the Include Image on Label switch is OFF.

Just tap the icon you want and you will see a preview of the labels with that icon, on the next screen. You might have to scroll down to find the icon you want.
The image will be placed on the left-hand side of the label, taking up a maximum of 25% (1/4) of the label. The image can be made smaller, and more transparent, if desired, by moving the sliders at the bottom of the screen.
If you cannot find a suitable inbuilt image, you can use an image in your device’s Photo Library, by tapping the Photo Library button.

Please note that the image selected will apply to the current list. You can choose different images for different lists e.g. c Christmas icon for a Christmas list, and party balloons for a Birthday list.