The original photo is of the SG 116 'Zellendusche' installation on one of two Fw 190 F-8s so equipped (White 11 and White 3) belonging to Jagdgruppe 10 at Parchim. Jagdgruppe 10 was the successor to Erprobungskommando 25 which previously carried out many experiments with novel armament.
The weapon is essentially three recoilless, single shot, upward firing 30mm MK 103 barrels, set with a two degree spread and fired by a photocell, the opening for which is visible at rear of the canopy. The two aircraft carried out tests with the system, using an old He 177 as the target aircraft. The tests were carried out in the second half of 1944 and yielded unsatisfactory results. The system was never used operationally.
Incidentally the installation on the other aircraft (White 3) was slightly different, the barrels being unequally spaced.
Cheers
Steve