A visual bug

Was making my black stone castle and I needed to get my dog onto the second floor. So I built to the roof and the dog follow, I placed glass panes under the dog so I can lower it down. (This is where the visual bug appears), when I go to hit the panes it illuminates the dogs complete online, making me able to see it through. It also works when I punch the lantern next to it, imagine will show further.