What is the enveloping action in regards to the story's sense of the "times" and characters' interaction with social currents in "A Hunger Artist"?

Your question seems to point towards the importance placed
on the passing of the times and how what is in vogue one moment becomes anachronistic
the next moment. Note how this is referenced from the very beginning of the
story:

During
these last decades the interest in professional fasting has markedly diminished. It used
to pay very well to stage such great performances under one's own management, but today
that is quite impossible. We live in a different world
now.

The tragedy that the
hunger artist suffers is shown to be completely outside his control. He and his art are
subject to forces greater than he can manipulate: the nature of "entertainment" and what
is considered a saleable art form. This understandably creates a sense of massive
frustration within the hunger artist as he finds himself, almost overnight, deserted for
more poplar attractions. In fact, the text explains, audiences now have a "positive
revulsion" for fasting.

Reference is thus made to the
fickle nature of the masses and their lack of comprehension of what is "art" and their
inability to truly appreciate it when they see it. It is the frustration that the hunger
artist experiences that drives him to sublime excess in his art, to fast beyond the time
that he had been allowed to, and to finally be able, in an act of defiance, to achieve
the ecstatic artistic heights that he has desired to achieve for so long. The irony is
of course that he only does this as a forgotten individual, a memento from a previous
era, and nobody records his achievement.