Janet Dawson answered:
This was done in one piece on a wider loom. Technically, it could have been woven on an 8S Baby Wolf using a technique called double weave that lets you weave two connected layers of cloth, but that's not a project for a new weaver or the faint of heart. ;) The most important things to pay attention to when you're planning to seam together two pieces of cloth is your selvage where they'll join, and your beat. Since one selvage of each piece will be right in the middle of the cloth, you really want it to be neat and tidy, without any big divots or loops. Because you'll be joining the two pieces together, they need to have the same beat for the cloth to drape the same way, or else the seam might pucker. It's especially important when there's contrast between the warp and weft, or where you've woven weftwise stripes, since your eye will pick up any mismatches easily. If you're doing stripes, be sure to use a guide tape as in the video - mark it with the exact width of the stripes as you weave the first piece, and then use the same tape and match it exactly while weaving the second piece.