In the 1969 episode, SG1 goes too far forward in time, where an old Cassandra turns them back. Every piece of equipment, in future StarGate room is covered by sheets.
Up until now I always assumed those were "not in use" covers, similarly to how furniture is covered when not in use.
Is this the case, or was the equipment covered to not expose it to past SG1 eyes ?
It was just an indication that the Stargate Command was not longer in active use. Nobody seemed to be there except Cassandra, who was only present because she had (presumably) been previously informed that she would need to meet the SG-1 on that date.
It was also a callback to the very first shot of the SG-1 television series, which featured the gate room and control room draped in cover cloths, indicating that the facility was in the process of being mothballed.
