iCloud Shared Album mishandles automatic conversion from HEIC to JPEG

In the screenshot below ...

On the left: An HEIC image converted to JPEG using a Finder Quick Action.

On the right: The identical image is moved into an iCloud Shared Album as viewed online. Same issue when viewed in Photos (10.0).

Therefore the obvious workaround is to convert such a HEIC image to JPEG before moving to a Shared Album.

- Pie Lover