Simply put, the entirety of 1 "frame" has more data than required, but a CRT TV would hide those "error margins" behind the borders. Your digital capture however has grabbed all the available data, and the pro would have done the same, but they would have then cropped it down to the desired area/resolution. You can see this when you compare the videos side by side, as the baby is "longer" in the pro version.
Simply put, the entirety of 1 "frame" has more data than required, but a CRT TV would hide those "error margins" behind the borders. Your digital capture however has grabbed all the available data, and the pro would have done the same, but they would have then cropped it down to the desired area/resolution. You can see this when you compare the videos side by side, as the baby is "longer" in the pro version.