English Language · Reading Comprehension

Read the following passage and answer the question that follows: 'The act of sculpting is frequently used as a metaphor for the birth of a concept. A raw block of stone holds a 'trapped image' that the sculptor seeks to liberate. This image represents the spark of inspiration that is not yet visible to others. The process is laborious; the stone does not yield its secret easily. Much like the development of a literary work or a painting, the sculpture emerges incrementally. Each chip of the chisel brings the artist closer to the final form, illustrating that creativity is a gradual progression from a vague internal thought to a concrete external reality.' Based on the passage, what does the 'trapped image' symbolize?