I realize that it looks liked the Used Magazines Patrol is coming for this lady, but really it’s a Robert Gibson Jones cover for Amazing Stories, December 1945. An interior illustration by Julian S. Krupa and accompanying text makes what’s going on clearer.
This issue of Amazing Stories is available to read and download from the Internet Archive.
It is the rule in pulp: no one and nothing is more interesting to a bizarre creature than a comely female human, and this cover by of the February 1940 Fantastic Adventures by Robert Fuqua (1905-1959) exemplifies the rule. I think it is probably illustrating Bertrand L. Shurtleff’s story “New York Fights the Termanites,”, although an interior an interior illustration by Julian S. Krupa (1913-1989) suggests a different conception of the beasties.
It looks like a pretty normal rush-hour on the 6 train to me.
This issue is available to read and download at the Internet Archive.