The whole set-up of the story is colonialistic. Quite apart from the pursuit of the Yeti, the western characters treat the locals as mere servants (at best) or superstitious savages (at worst). But there is some effort at least to portray the people at the monastery (who I assume are meant to be Tibetan, as they are headed by a Lama, though it's never specified) as having a real and valuable culture of their own, e.g. via early establishing scenes in which their Lama shows a local knowledge of plants unknown to John Rollason's science. There is also certainly a fully developed critical contrast between Rollason's scientific curiosity, driven by the desire to achieve a greater understanding of humanity, and capitalistic greed encapsulated by an American member of the expedition, Tom Friend. Friend in some ways appears ahead of Rollason in recognising the capacity of media like television for opening up mass access to knowledge. But ultimately he just wants to show the Yeti on TV for his own benefit, as we realise when he turns out to be happy to claim that a monkey they've trapped is the real Yeti, and then also causes death of another expedition member by giving him blank ammunition so he can't harm a real Yeti in the process of trapping it.
Cushing is of course everything you'd hope for as Rollason. There is a lovely example of his famous facility with props early on, when he is presented with a purported Yeti tooth while still in the monastery, and rather than just turning it over in his hand while delivering his dialogue, he immediately whips a tape measure out of his pocket and takes its dimensions. This is followed by a very interesting editorial cut directly from a close-up of the tooth to the mask of some kind of mythical being with one tooth missing being shaken in the air during a religious ceremony in the monastery courtyard, perhaps designed to suggest that the circumspect locals know of and venerate the Yeti. Though Cushing had already done The Curse of Frankenstein by this time, Hammer were still using colour only for their horror pictures. This one is more in the line of fantasy / action, so it remains in black and white, but conveys its Himalayan setting via some very impressive location footage filmed with stunt doubles at La Mongie, a ski resort in the French Pyrenees. Combined with sets at Bray (the monastery) and Pinewood (the mountain top locations) for the actors and a matte painting for long shots of the monastery by Les Bowie, it does a pretty decent visual job by the standards of its time.