Fetish is not necessarily sexual, but it is definitely an enchantment or spell that affects people, often profoundly.
A female peacock has a fetish for brilliant plumage, as do most birds.
Bees have a kind of fetish for flowers that is “nutritional” rather than “sexual” for them, although from the flowers’ perspective it is clearly a sexual situation.
Male humans in North America tend to have a fetish for female breasts.
Fashion, generally, is a form of fetish in which visual images evoke emotion.
For that matter, just about anything that is not a sex organ that evokes any emotion could be regarded as a fetish.
The question as to why some things evoke emotion and others don’t is, of course, a mystery. Another mystery is why do some things evoke an emotion in some people (or animals) and not in others??
Some fetishes are instinctive or genetic, such as those of birds and bees. They are probably not acquired through cultural influences. In contrast, a breast fetish, for example, is probably the direct result of a mixture of infantile fixation and the cultural taboo against nudity.
A prime example of the fetish that is not of the sexual nature would be a voodoo doll. It is capable of invoking a substantial emotion yet there is no discernible connection with sex.
Fashion is somehow probably connected to “herd dynamics” and related to the survival of the fittest mode. In a sense, we are inclined to “make babies” with the best dressed people in our herd because they appear to be the most successful in life and, therefore, would make a better genetic contribution to our progeny.
In any case, fetish can be considered to be a form of “enchantment”.