MrsJones, I would never shun you.... as long as you don't shun me.
I suspect you have it right - she was showing some level of arrogance, or class-distinction. Plus she obviously was more interested in flirting with the guy behind you than doing her job. Is there such a thing as predudice among the sista's over 'shade's o' color'?
Likely she was just a bitch.
Jeff