A "mirrored ceiling" refers to a ceiling that has reflective surfaces, typically made of mirrors, which creates a visual effect of duplicating what is below it, making the room appear larger or adding an interesting design element. Full definition
The spacious interior includes three large family / living rooms, dining room with mirrored ceiling with ample seating for a large group, a chef's kitchen and large bar for entertaining. (moneysense.ca)
We use materials in a surprising way — for example, combining a gold - mirrored ceiling above a pool or an oversized carpet made to look like timber. (livingetc.com)
What do mirrored ceilings, nude portraits and strip lighting have in common? (idealhome.co.uk)