Update barcode scanning images

We want to wait to see if anyone has any feedback on the new designs, but once we feel confident we want to update the images so people know they can rotate the device etc.

Start by reviewing the proposed barcode-scanning designs and locating the current barcode-scanning images in the documentation. Confirm the final designs and device-rotation guidance with maintainers, then replace the relevant images and verify the rendered documentation.

Written by the indexing model from the issue text.