Risk and uncertainty-Example 1

Dear tutor,
While creating the matrix for probable profits, then doing the maximin, maximax etc, the contract size is on the left and the demand is on the top. How do these two correspond to each other? In the given example, the first demand figure is 400, and the contract size being 300. Is it like when the contract size is 300, demand is 400? Do the contract and the demand occur simultaneously?
If not, how can the two be pitched in a matrix and combined to arrive at best/worst outcomes?
Thanks in advance!