See this for "Other" storage: https://support.apple.com/en-us/HT202867
Is your Mac a MacBook or MacBook Pro and are you using Time Machine? Then the big "Other" could be local snapshots - Time Machine backups made and stored locally, because you have not made a regular time machine backup for some time. These will be removed, once you run Time Machine again to create a regular backup, or if you need the storage. The local snapshots can be confusing, since deleting a large amount of photos will result in moving them to the local snapshots, and we do not see, that storage has been freed immediately.
Deleting photos as described by Gail should be making your Photos Library smaller.
You seem to be comparing the total free storage on your Mac before deletion and after deletion of photos, but have you compared the size of your Photos Library before and after you delete photos? Does the size of of the Photos Library decrease, after you delete photos? I want to find out if there is some system trouble or a problem with your Photos Library.
Are you now seeing a "Recently Deleted" folder if you delete selected photos with command-delete or is this album still hiding?
If you cannot make the "Recently Deleted Album" appear, repair your Photos Library (Repair your library - Photos Help).
If deleting photos does show the Recently deleted album, but the library size stays the same, when you empty this album, your photos may be stored outside the Photos library. Have all your photos been imported with the option "Copy items to the Photos library"? Importing to Photos without copying into the library means that you are managing the photos yourself - they are stored outside the library, and Photos ccannot delete them, when you delete photos from Photos.
Are you using iCloud Photos in any way?
The only other reason I know of for the size of a Photos Library not decreasing after deleting photos is a damaged library. If you have been using cleaning applications like "CleanMy Mac", Photos may no longer be able to retrieve the photos for deletion.