This is what it says, that the record is still held fast in shrink-wrap. We tend to be pretty suspicious about these things, so if the shrink-wrap doesn't look original, or if the record seems to have undergone some damage over time, we'll probably take it out of the wrapper to ensure that it's in good shape — which is why we don't have more of these. In some cases the shrink-wrap may be torn in spots, but if it's not possible the record has been taken out and played, the record will still qualify as "Sealed".
If something is noteworthy, we try to note it in the comments — especially if it is an oddity that is the only wrong thing about the record. This might include, but isn't limited to, warped records, tracks that skip, cover damage or wear as noted above, or strictly cosmetic flaws.