No, another lines-woman

At this low resolution the clip can't really show it, but the expression this lines-woman wore after Serena dumped a return into the net was hilarious.

I don't think I have seen a lines person show such interest in a match before. But I agree with her assessment of Ms. Williams, er, I mean the shot. Hi Def was much easier to see, but no recorder for that just yet. Here's a still: