I just created a new release of an old album with the correct cover art
Basically I downloaded a copy of the correct image from one of the other releases and then added it to the new one that I just created. This worked well, but I now have to uncheck the “Download only approved images” option for it to show up in MusicBrainz Picard.
Is there a way to have the image approved somehow, so that it shows up with the default options?
That will happen after expiration on [the edit] (https://musicbrainz.org/edit/44670149), so 6 days from now at the latest 
I would like to point out that, a lot of the time, releases will have very slightly different covers; for the front, especially when it’s as sparse as this, the differences are probably not going to be significant, but given that that’s the closest most people will get to the physical CD, we tend to rely on the art for verifying our data. Copying the front cover over is certainly not a bad thing to do, but you should probably add a note that you’ve done so; see my followup edit.