msphiRSI wise, is playing with straighter arm safer than with a retracted arm? (like this: https://i.ytimg.com/vi/ojR_qedzzK8/maxresdefault.jpg)
I think what he meant was having your arm parallel to the table or the ground (i.e. not having it slanted at an upward angle if your desk is too high)
don't think it much matters if you're sitting diagonally and don't have your arm completely perpendicular to the edge of the table
ive had to sit diagonally like the guy in that image with my keyboard in my lap and have found it's really hard to have proper posture and not strain my left wrist (the keyboard hand)
my problem is that my chair has wrist rests but they're too low and so I can't rest my arms and also reach the surface of the desk to use my keyboard, and if I have my keyboard in my lap they just get in the way or I have to put my wrist at a super awkward angle tilted downwards
would definitely recommend (if you have the ability to; my dorm came prefurnished so i don't have much of a choice) getting a proper desk/chair so you don't have to strain your wrist super hard