Hi Edward, welcome to the Apple Users Community.
Apple encourages this, it is the settings on your machine that are making it difficult for you.
First I suggest you let us know the Hard Drive you are speaking of, would this be an internal HD, a USB Flash Drive or perhaps an external SSD?
Are your pictures in the Photos App on your MacBook or are they in your Pictures Folder?
Do you allow Hard Disks and External Disks to show up on your desktop? This is an old school setting that is not commonly used today but it could be useful in this instance.
This would not be a workaround instead of iCloud, this is best practice because you may not always be in a situation where internet access is possible and backups may have to be done even so.
Look forward to hearing back from you.