Final answer:
The metaphor of an expansive balloon held down by fragile threads illustrates how potential can be restricted by minor factors and may relate to the theme of finding beauty in harmful situations as the author of the poem does.
Step-by-step explanation:
When an author mentions "an expansive balloon held to the ground by two fragile strands of threads," this metaphor is often used to convey a situation where something with the potential to rise or expand is being restrained by delicate or minimal forces. It could suggest a dynamic where significant potential is kept in check by seemingly minor but crucial factors. For example, an artist may be brimming with creative ideas (the balloon) but held back by a lack of resources or confidence (the fragile strands).
In literature, metaphors are a powerful device that authors use to illustrate complex ideas through simple imagery. In the context you've provided, it seems the author is drawing a comparison to highlight the theme of seeing beauty in harmful or destructive situations. Similar to the believers finding beauty in the destructive flames or the speaker admiring the polluted ribbons, the balloon metaphor might symbolize something inherently promising or uplifting that is, paradoxically, being tethered by something harmful or inadequate.