Two parallel senses: literal flapping (wings, fan, fire) and figurative inciting (people, emotions, unrest). The 'incite' sense is interchangeable with
煽动 (shāndòng, same pronunciation, same meaning) — these are two acceptable spellings.
煽 (with the fire radical
火) is now more common for the 'incite' sense;
扇 stays for the physical 'flap'.