Possibly taken at the Lympne light aeroplane trials?
Well going through Arthur Or-Hume's book "The Lympne Trials" I could find no reference or photographs of the aircraft only two aircraft fitted with a British Anzani v-twin are listed and they were an ANEC II, G-EBJO and a Hawker Cygnet I G-EBMB . The OP states that the aircraft was operated it from various small fields in Kent. So presumably it was registered.and possibly around 1924.