Since Draper did furniture for him and since it looks like something he'd have done i'd say that in the absence of names to the contrary it's Draper's in that first pic.
I won't rule it out totally. Arnold's decorator, Waldo Fernandez, stated that they searched high and low for the right desk for Arnold, but had not luck and had to have one custom-made.
Now, whether Arnold suggested Draper to Waldo to make this desk is anyone's guess, so who the hell knows. *shrugs*