High ceilings and classy chandeliers with lots of flock wallpaper and plenty of uniformed staff. There would have been no en-suite bedrooms and the linen would have been just that, linen rather than cotton but very fine linen. I doubt that the bedrooms had much to offer, maybe a sofa and a small table but in Brighton good windows would have been a must, which opened to let in the sea air.
Downstairs there would have been a writing room with dark wooden furniture and embossed note paper,. possibly a smoking room and a large dining room with linen table napkins and quality table silver.
There would have been a quiet lounge for tea.
Find a history book, look up some photos of Victorian and Edwardian interiors and then use your imagination. And good luck with the novel!