It's in active growth. The shoot farther up the stem may be separated and potted up eventually, but the bigger it is when you do that, the faster it will mature.
Yamamoto Dendrobiums [had] detailed care instructions for nobile types on their Web site.
Edit June 15 2020:
Yamamoto Dendrobiums in Japan hybridizes and produces a great number of these plants. Their Web site formerly had excellent growing information for hobbyists. Unfortunately it is no longer there. You can still look at the varieties they grow, and maybe see one very similar to yours.
I saved the page, and summarized it in a post in this thread:
Uncertain if Dendrobium is still alive
Yamamoto now has a
page showing how to force Dendrobium nobile for Christmas flowering in Japan's climate. There is a lot to learn from that page, but it is intended for growers who can artificially heat and cool their greenhouses during off seasons. Note they use coconut husk for growing medium, which many orchidists would say retains too much water for orchids. For many orchids that is correct, but this is a very thirsty orchid.