Market and positioning strategy
The lab determines who your product is for, which problem it removes for them and how it should stand against the alternatives they already use. That judgement is made from how the software actually behaves, not from a category label, and it is revisited when the product or the market moves.
Go to market strategy
It decides which routes your product should reach its market through and in what order, and states what has to be true for each route to work. Sequencing matters more than breadth: a route is taken on when the product is ready for the customers it brings.
Messaging and narrative
The lab defines how the product is explained, in language precise enough to survive contact with the software. Because the narrative is written by people who understand how it works, it stays accurate as the product changes rather than drifting from it.