What is a packer?
"Packer" is a full brisket. It looks like what you have there is just the flat. I prefer the full packer brisket myself because I can find them for a significantly better price per pound than the flat and I think they smoke better.
I'm not familiar with butchery so I may be wrong completely, but that cut of meat is only 6 pounds. I guess that may be why they gave me the flat only?
Am I correct in assuming I would have to get way more than 6 pounds of meat if I wanted the packer?
The last packer I smoked was 13.5lbs (definitely on the small side)
If you ask a butcher for a packer brisket they would know what it means, I bought mine at Costco.