The 2 temp readings are for the main body of the console and the 2nd for the hot air that comes out the back.
I'm guessing he didn't show 2 different readings on screen for the XB1 as the temp was around the same for both readings, Only reason why he didn't show it I'm guessing.
He didn't take them apart to test the component temps though as that would truly be entering anorak territory ^_^
It's pretty worthless information then. I can see why for a handheld device like a phone or a laptop external surface temperature is important. However nobody sits around holding their console so how does knowing that help.
I guess knowing the core temperature would show which has the most thermal headroom and that would in some way prove which console was closest to its limits. If you want to make the statement that the PS4 runs hotter then they are the lengths you need to go. Measuring the power consumption would be the easiest way to establish which kicks out the most heat.
JR