What does the cryptic crossword clue "Imagine writer dropping names? It's a sign (3)" mean?

The definition is "sign". The wordplay uses a deletion. LEO (deletion) + (deletion) = LEO; definition: "a sign" The answer is LEO.

Imagine writer dropping names? It's a sign (3)

Guardian Cryptic #29138 | 12 Across | 2023-08-02 flower