Definitely arm warmers. You can see the layer separation on his arms
I agree - although they probably what we call arm screens (no fleece) which are more about sun protection than anything else. Might have an aero function on the bike but he's obviously kept them on through the run too.
Downstairs it looks like he's wearing jeans with a cowboy buckle that was designed by Jonny Ilve....or is it just the photo? Tough to go 7:55 in jeans.