You can loot as passenger on a 2p flying mount (tested with sandstone drake) and loot window wont disapear
Person 1 mounts up on a 2player mount
Person 2 jumps on
Person 2 loots dead mob
Person 1 flies somewhere else
Person 2 is still able to loot the corpse
Could also take the loot from corpse and sell to vendor, since opening vendor tabs wont close the loot tab
Quick observation, it seems to have a limited range, but when I fly past other corpses I havnt taken all loot from they come in the loot window aswell, so this could be used for AoE looting since it covers a much larger area than regular AoE loot.
Edit: the range we're talking about is around 100-250 yards
Did quick search, didnt see any other posts on this, bit tired so mightve missed it.