What does the cryptic crossword clue "Copies I need to revise at times (8)" mean?

The definition is "Copies". The wordplay uses an anagram. anagram of I + AT + TIMES = IMITATES; definition: "Copies" The answer is IMITATES.

Copies I need to revise at times (8)

Guardian Cryptic #26526 | 24 Across | 2015-03-23 flower