Answer:
Metaphor.
Explanation:
Figurative languages are the words that writers use to convey meanings to their works through the use of unconventional words. These elements of writing provide colorful clarity with a much clearer detail in presenting the work.
In the given expression of using the phrase "sinking coffin" from "Refugee" by Alan Gratz, we can say that this is a metaphor. Metaphors are used to compare between things or events without the use of comparison words such as "like" or "as". And in saying that "it was a mistake, leaving on this sinking coffin", Lito compares the overcrowded boat to a coffin, an image of death.
