Maybe a tad harsh.....but i guess by your post, you think it appropriate to be rude to a higher ranking crew member. Most airlines are quasi-militeristic - that is they have a chain of command albeit less strict than the military. The command is governed by 2 things. 1. Law - in Australia the civil aviation orders and regulations, and 2. the company. Unfortunately some CSMs and cabin crew seem blissfully unaware of this. In at least 1 case the Captain bypassed the company, went straight to CASA and had CASA remove her.
Whilst 99% of crew co-exist in a friendly relaxed manner, this is not an excuse for poor behaviour. The CSM is meant to lead by example. She is aslo meant to show some respect to her senior crew members, whether she respects them or not.
In this case she could easily have asked the F/O if he could put his bag somewhere else, but instead she has been "rude" from the outset. - and from the sounds of it, she wanted to cause a stink.