[swarmee]

Here's an example:


According to PSA's grading standards at https://www.psacard.com/resources/gradingstandards/ , a PSA 6 with no OC qualifier "must be 80/20 or better on front..." 80/20 means that one border is 4x the size of the opposite border.
This card looks like it's right at 80/20 to me, visually. If the card was otherwise Gem Mint (PSA 10 quality) or Mint (PSA 9 quality), PSA would have given it a 9(OC). There is no 10(OC) since Gem Mint cards cannot have qualifiers. If it was given an 8(OC) because it was in the condition of an NM-MT card, some people would prefer that to a straight PSA 6, most would not. But those people who wouldn't buy a card with a qualifier also aren't going to buy this one as an off-centered PSA 6, for the most part. Despite being a PSA 6, this card would likely sell for a PSA 4-5 or so price.