Final answer:
Rosemary's motivation for stopping by the antiques doorstep is likely linked to a desire for social mobility or change, paralleled by Maria Macapa's actions in her quest to collect junk and sell it for small profits to dress like the elegant soda-fountain girls.
Step-by-step explanation:
Rosemary's motivation for stopping on the antique doorstep is intricately tied to Maria Macapa's behavioral patterns and her interactions with the surrounding characters.
Maria's relentless search for junk to sell to Zerkow indicates her desire for money to emulate the soda-fountain girls, whom she admires for their elegance and connection to the world. Moreover, her disturbances around the flat suggest a profound impact on the residents, such as Old Grannis and Miss Baker, who are interrupted by Maria's intrusions.
Yet, despite the annoyances she causes, there is an underlying indication that Maria's motives are rooted in a yearning for a better social standing and inclusion within the community. Hence, Rosemary's decision to stop on the antiques doorstep may be steered by a similar desire for social mobility, the pursuit of a dream, or the desperate need to alter her current circumstances, mirrored through Maria's actions and the collective yearnings of the characters around her.