The inverter is connected to the battery in both methods. But the SCC can be connected to the battery as usual, or routed through the inverter DC input as in the video.
No practical/functional difference as long as all the wires are sized and fused correctly for the current they'll carry and the terminals can support more than one lug.
In that particular video I guess that Will wanted to build a very compact setup with short wire lengths (that required no crimping and wires you could buy at Walmart). So he used the inverter terminals as a convenient location to make connections rather than running two sets of long wires to the battery. The goal was to make it easy for a beginner to wire up and that topology is dirt simple.