Main curtain. Sketch of the scenery for the drama by M.Yu. Lermontov Masquerade Alexander Golovin (1863-1930)

The picture has something of this: decoration, ornate, gold, culture, design, imperial, style, retro, texture, traditional, symbol, temple, fabric, antique, luxury.
Perhaps it’s a drawing of a red curtain with gold trimmings and a diamond on the top of the curtain, with a diamond in the middle.