A procession of gaudy marionettes, yet with something of the relentless horror of Frankensteins in their detached, mechanical unawareness
This quotation is taken from the stage direction in Scene Five. The references to human "liveliness" are indicative of class in the play. O'Neill describes both Mildred and the people on 5th Avenue as distanced or detached from "life." Mildred tells her aunt she wants to "touch life somewhere," help "life" like Yank and others who inhabit the poorer classes. Mildred's inability to actually communicate or "touch" life is clearly revealed in her encounter with Yank. The instant Mildred sees Yank, her expression of intense fear, is perhaps her most "real" moment in the play. In this moment Mildred is forced to come out from her veil of superficial expression and politeness—Mildred is confronted with the basic fear of survival. Furthermore, the poorer classes who have such fears on a daily basis are seemingly more alive than those who spend days shopping on 5th Avenue.
This stage direction also dictates a specific physicality among the actors. They should move as "gaudy marionettes"—being pulled and directed by a puppet master overhead. How literally each stage production will take this direction will certainly vary. Nonetheless, O'Neill implies that these people have evolved to the point where they have become artificial. Artificial in the sense that they are manmade—controlled and manufactured solely by human business, commerce and pleasures. Where class has pushed down and smothered the poor, it has also lifted the rich above nature and an association with the animal.