So I tracked down the technical paper that is specific to this FA20 engine, and it clears up a few things (see end of post where I have attached it). The spray pattern appears to be a single fan spray, angled differently than the old twin-spray pattern for V6 applications:
That makes sense considering it is a boxer engine. Here's an image showing a comparison between the FA20 intake port and the FB20 (basic naturally aspirated Impreza engine with PFI)
As I've said in the past, the fan-type injector is currently on used on Toyota D-4S engines. How about a comparison for context. What would a different DI spray pattern look like? Let's briefly examine the Porsche 997 turbo:
That's a multi-hole spray pattern with a high charge-motion port, designed for fast combustion and knock relief on a turbo engine. There are no port injectors. However, Porsche uses a high lift cam profile and multiple DI injection events for knock relief and more efficient combustion:
You can see the use of three injection events at low speed full load. This is unusual on solenoid DI injectors, as usually only piezoelectric A-cone injectors employ three injections. Compare that to our FA20 operation map, with fixed cam lift and as far as we know single DI injection events only:
So you can see a nice comparison there between combustion highly optimized for a high flowing, high revving n/a boxer application versus one highly optimized for a turbo. For reference, see attached paper on the FA20.
Development of Horizontally Opposed
2.0-liter Natural Aspiration Gasoline Engine
for Subaru BRZ