An image is usually the scan side view of a postcard but it may be a scan of any other type of document or a current photo. Some objects have a clean image like the ones listed below.

- address side of a card
- scan of an envelope or notebook
- modern photo
- photo card
- detail of a map
- poster
- stamp or postal sticker

Other objects may be associated with an image. For example, an encyclopedia term does not have its own image but can be linked to an image.

Some images are not accessible for copyright reasons. Indeed it is necessary to wait 70 years after the death of the author for the image to be free of rights.
Some images that are not from the internet and are scans made by members are only accessible to members

Finally you have to scan at 150 dpi (or dots per inch) to load a scan as well as the image size is too large for the website.
You can scan at higher resolution but it will be necessary to reduce the weight of the image to load it on the site (either by reducing the size, or by reducing the quality.

It is not necessary to load the back of a card but it is useful to load one for a series or a particular set (to identify the series or date the card)