I've reported most if not all potential issues that have been mentioned here and steam discussions to our development team. They are currently looking into the problems and working on finding fixes.
Crash issues take priority, of course, but, if they do try to fix visual issues as well (though since Atelier Sophie and Firis visual issues were never fixed, I guess these will be ignored as well in Blue Reflection), I think the bigger ones are the poor shadows and ambient occlusion, and the low quality FMVs.
Shadows and ambient occlusion wise, this comparison is made from youtube videos so their quality isn't great, but it's enough to tell the difference:
http://screenshotcomparison.com/comparison/118867
Shadows overall just look better in the PS4 version, and there's also what I assume is poor ambient occlusion in the doors and door windows in the right?
Same with the lights at the top in this shot:
http://screenshotcomparison.com/comparison/118526
There's even scenes with missing shadows in a PC version (bottom left):
http://screenshotcomparison.com/comparison/118533
As a side note, if the dev team doesn't ignore visual issues in the PC version for once...
Could they go back and fix Atelier Firis? :<
http://screenshotcomparison.com/comparison/118869
PS4 has much more natural lighting, and PC has much worse bloom (lamp) and is missing ambient occlusion... PC just looks so much flatter in comparison to PS4.
And then there's also
weird shadows issues.