Years ago I stored my clivias in a cool, dark basement room for several months, then brought them into a bright living room window. They always came out of the dark with scapes elongating nicely. The plants performed admirably despite being in total darkness for several months. They never bloomed on short scapes.
Now I have a young plant which first bloomed in mid summer on a somewhat short scape. It is now in my chilly back porch plant room under fluorescent lighting. It is blooming again on a short scape. A nearby Clivia gardenii is also blooming, but on long scapes. I have cross pollinated them, hoping to obtain hybrid seed.

During the winter, I keep clivia indoors and give it very little water...a splash once a month. In summer, I take it outside in the shade and it blooms beautifully. Keep it pot bound as it likes the roots tight.

mine as well I left it in cool basement last year and it surprised me with a lovely long scape bloom. This year I left it in the dining room with better sun and warmth. It is now flowering much the same as your foto. Perhaps it needs the cool to grow the scapes?