The Morgan Library & Museum website explains that the exhibition spans Holbein's career, and "In addition to showcasing Holbein’s renowned drawn and painted likenesses of these sitters, the exhibition highlights the artist’s activities as a designer of prints, printed books, personal devices (emblems accompanied by mottos), and jewels." It really does sound like a wonderful exhibition.
Don't worry if you can't get to New York, though, as you can explore the exhibition online at https://www.themorgan.org/exhibitions/online/holbein with their 3D video tour. Enjoy!