Looking at TrekCore's Reunion screencap gallery, there certainly seems to be plenty of close-ups... but also a good deal of other kinds of shots. It doesn't look that far off from other episodes, to me anyway. Television is a close-up medium, even today. That aesthetic seems to be creeping into motion pictures more and more (look at J.J. Abrams' work -- and he came from TV, of course. Or Joss Whedon, for that matter). In addition, you have to understand that before the advent of HDTV, back when TNG was filmed, television required the use of a lot of close-ups due to the lack of picture resolution in NTSC video. Otherwise, it was hard to read the emotions on the actors' faces.
It's probably just a directorial style. Frakes intentionally framed some of the shots of Worf & Alexander lower so Worf would appear to tower over him. Brilliantly directed episode!
I've always been more interested in knowing why Suzie Plakson kept blinking while talking with Picard via viewscreen. Did she have something in her eye? --Sran