A camera can record a RAW file and a JPEG for the same photograph. When that pair is imported into Photos on Mac, Apple says Photos uses the JPEG as the original by default. If your editing task requires the RAW member, choose it deliberately before evaluating the result.

First confirm that you actually captured and retained the pair. A JPEG-only image does not acquire the missing camera RAW data by changing a menu selection. Keep the original camera files and a usable library backup while testing your workflow.

Select the editing original

Open the paired photograph in Photos, click Edit, then choose Image, Use RAW as Original. Begin with one representative photograph rather than changing the basis of an entire finished project at once.

Compare details relevant to your intended edit, such as a bright area or a subtle colour transition. Keep the comparison conditions consistent. A different-looking image is something to evaluate against your purpose, not automatic proof that one version is preferable.

Treat reprocessing as a separate decision

Image, Reprocess RAW is a different command. Apple explains that RAW processing can change with camera compatibility updates or macOS updates. Reprocessing applies the newer processing to an imported RAW image; it does not merely choose the RAW member of a pair.

Apple warns that the appearance may change and the reprocessing change cannot be undone. If the current rendition is important, preserve an accepted output and the library backup before considering it. A dimmed Reprocess RAW command means the processing is already current.

For an existing delivery, compare the accepted rendition with any proposed change before replacing the issued file. Record which original and processing decision you used so a later edit does not accidentally start from a different basis.

Leave satisfactory images alone when there is no reason to change their processing. The useful outcome is a conscious choice of source and processing, with the original material still available, rather than applying every command that contains the word RAW.

References: Apple: choosing the RAW original, Apple: reprocessing RAW files.