If a client cannot see the photos to download, several things might have occurred.
Check if the photos for the client have been uploaded to the "Photo transfer" tab.
Make sure you clicked "Share with the client" in the "Photo transfer" tab.
Ask the client if they looking for the photos in the correct tab - the files are located in the "Photos to download" tab (second to the right from the "Photos" tab).
Computer:
Phone: