OK... i could definitely be wrong - so here goes:
If you don't sysprep a machine properly with a generalization, it doesn't make a new machine SID. The local accounts would therefore have the same user SID (with a -500 RID for administrator accounts).
Joining the machine to a domain after this, would result in a unique domain SID (Computer), which is what is used for domain security/access.
So the report tells me that i have workstations that weren't generalized properly when deployed, and have the same SID for local accounts. Therefore, since the account SID is based on machine SID, Lansweeper named the report a Computer: report, as that means the computer SID is the same... but that doesn't really matter if they are on a domain, as nothing really uses the local SID outside of the box itself. The domain SIDs are all unique though.
Correct me if i'm wrong, anyone.