When this woman feels torn about train etiquette, she asks Reddit:
I (f, 30s) was riding an almost empty train, there were maybe 5 or 6 people in the whole carriage. I sat in a four-seater (two seats on one side, two across) and spread out my stuff, put my jacket on the seat across from me and put my feet on it so that the seat wouldn't get touched by my socks. If it matters: It was early in the morning and I had been wearing these socks for less than an hour. My shoes are also clean as I alternate two pairs daily to let them dry out between uses.
A guy in Innguess his late forties or maybe early fifties entered the train, came straight to me and said 'move your bag'. I was puzzled since there was plenty of free seats to go around, so I asked if he really wanted this particular seat and he said yes. So I picked up my bag, he plopped down next to me and I proceeded to pack up my laptop, drink, jacket, put on my shoes and moved to a different four-seater. I spread out again.