Answer: his sentence contains multiple literary devices. so it is kind of up to you to interpret this the way you want.
Step-by-step explanation:
"Heap of metal being swallowed by a greedy mound of blackberry brambles" is a metaphor. It compares the heap of metal to something being consumed by blackberry brambles, suggesting that it is being taken over or consumed by something else.
"Greedy mound of blackberry brambles" is also personification, as it gives human-like qualities to the blackberry brambles, in this case, the quality of greed.
"Anonymous" is an adjective describing the heap of metal, but it could also be interpreted as an apostrophe, as if the speaker is addressing the heap of metal, giving it an identity or addressing it as if it were alive.
It's worth noting that this sentence is part of a larger context, so the meaning and interpretation of the literary devices may be different based on the context.