Final answer:
The poetic style device represented in the highlighted portion of 'The Tyger' by William Blake is Anaphora.
Step-by-step explanation:
The poetic style device represented in the highlighted portion of 'The Tyger' by William Blake is Anaphora. Anaphora is the repetition of a word or phrase at the beginning of successive lines or clauses. In the excerpt, the questions 'What the hammer?' and 'What the chain?' are examples of anaphora as they use the same structure and repetition at the start of each line.
Learn more about Poetic style devices in 'The Tyger' by William Blake