Understanding Your Ratings
Three separate rating fields can appear on an album, and they're easy to mix up because they all sound like "how good is this record." Each one answers a different question.
Pressing Quality
The reputation of this specific pressing or reissue itself — independent of the condition of your particular copy. A first pressing mastered by a well-regarded engineer might have excellent Pressing Quality even if the individual copy you own is worn.
Expected Audio Quality
How this record is expected to sound, based on the pressing, its stated grade, and its pressing history. This is an estimate, not a measured play-test of your specific copy.
Collector Rating — My Copy
Your own rating of the actual copy you own, based on your own listening or inspection. This one is never set automatically — it's entirely yours.
In short: Pressing Quality and Expected Audio Quality describe the pressing in general; Collector Rating describes your specific copy.