Thank-you for initiating this discussion. Perhaps we can get some clarity with respect to CA and how it should be prepared.
My understanding is that there are three purposes for the CA associated with MB on the CAA:
1, Provide archival information with respect to releases.
1a. Provide evidence / backup / source material for edits.
2. Provide images for tagging (particularly with Picard).
The image that you included above is an excellent example of archival quality information. I dare say that the vast majority of the CA images uploaded do not meet this standard, however; that’s certainly something that contributors can strive for in the future if this is the direction that MB wants to go (and assuming that purpose 1 is a valid assumption).
The archival quality submissions can also meet the requirements of purpose 1a, although that level of quality is not required. This non-archival quality status is where much (most?) of the existing CA falls. Users that are unable or unwilling to provide archival quality images, are still making a valuable contribution where such archival images are not already present.
The third type of image is used for tagging music files, and has generated considerable controversy in the past. Some users such as myself see that as square cropped cover images, since square images are what is returned by CAA unless the user specifies to retrieve the original uploaded image. Others prefer (and insist) that these tagging images be left at the original aspect ratio rather than providing a squared image. This debate has prompted me to request a new image type to identify a square cropped tagging image and a corresponding preference setting in Picard (https://tickets.metabrainz.org/browse/MBS-9407).
In order to provide clarity to CA quality for MB, I suggest that:
The MB brain trust decide and indicate the intended purposes that MB retains CA, and any preferences / expectations with respect to quality.
The users indicate how they intend to make use of the CA images, keeping in mind the MB position regarding intended purposes and quality expectations.
Depending on the answers to these two questions, perhaps additional attributes could be applied to the CA to indicate such things as “archival quality image” or “square cropped tagging image”.
I fully support the archival quality images, and intend to invest in the “reference target” strip if MB indicates that as their preference with respect to archival images.
Thanks again for bringing this up.