1. It's her Broadway debut, and her roots are actually in theatre.
2. She speaks in a solid Irish accent even though she, unlike the rest of the cast, isn't actually Irish.
3. The play is by Pulitzer Prize-winning playwright John Patrick Shanley (in the light brown coat) who also wrote Doubt and Moonstruck.
4. And, plot-wise, it's similar to Moonstruck, so Debra Messing is basically like an Irish Cher.
They're both women who keep getting nagged by their families about their age and how they haven't found a spouse, both tough on the outside and romantic on the inside, both strong women who drive the story and are really entertaining to watch.