The program is new, and apparently there aren't too many magazines so far indexed. And the ones that have been indexed, like Popular Science and Popular Mechanics and the Bulletin of Atomic Sceientists, aren't likely to turn up results of interest to me. However, one periodical that did yield some worthwhile results was New York magazine. Searching under "Louise Brooks" turned up a couple or three articles I was already familiar with, as well as numerous listings for screenings of Brooks' films (especially Pandora's Box) throughout the 1980's and 1990's.
The most unusual material I came across using this new keyword search ability was a couple of classified advertisements from 1995. The first dates from August, and the second from October, of that year. I wonder, did these two lonely souls with a penchant for Lulu ever meet?