Rhododendron bhutanense D. G. Long & Bowes Lyon, Notes Roy. Bot. Gard. Edinburgh 45: 327 1988 publ. 1989.;
East Himalaya as per POWO;
An alpine Rhododendron: 1 correct image as above.
An alpine Rhododendron from Bumla pass- 14000ft, Arunachal pradesh
I am sure that this image is of Rhododendron bhutanense. I have seen it few times.
References: POWO Catalogue of Life The Plant List Ver.1.1 IPNI GBIF (High resolution specimens) Bhutan Biodiversity Portal rhodygarden
Pictorial guide to Rhododendrons of Sakteng Wildlife Sanctuary (page 7)- June 2018- Sonam Wangyel, Keesang Dorjee, Jangchu Wangdi & Thinley Wangdi