I have not read Umineko, but I would like to take a bit of time to share a couple of scene redraws from this blog here. These are about the only things I’ve seen and remember about the VNs.
I can’t sort through all their tag and I’m actively trying to avoid spoilers. There’s no context to the screencaps, no text at all, only the sprites + background + redraw. Of course, there’s spoilers in their general Umineko tag (which has more redraws if you want to go look for them). I asked a friend who has read the VNs and she determined that these wouldn’t give away any information, so these were the three I chose to link.