Madame Leota hasn't cast her summoning spell yet when we're in the piano room, so there's no visible ghost here...but there are signs. We see his shadow and the keys are moving on their own, playing a version of Grim Grinning Ghosts that's written on the sheet music fanned out above. Our narrator has stopped talking for a moment since we left the library and its priceless first editions, giving us a minute to take it all in.
This room is dark and taking pictures in it is about nothing but maximizing light and then coaxing out every possible detail in edits afterwards. Settings were predictably extreme: 50mm, 1/50 seconds, f/1.2, ISO 25600. Embraced the resulting noise some and otherwise dealt with it in edits.
Fun Fact: Did you ever notice that there are two distinct colors/color groups of light throughout the Mansion? Most things are in shades of greens and blues and purples, but some things glow with amber light. If you look carefully, you'll notice that it's only the handful of living things—owls in the trees, a roaming cat, the groundskeeper and his dog...—that are lit with amber.