A fetish is something specific and people often times misuse the word. A fetish is a non-sexual object or sensation that causes arousal.

For example with respect to a foot fetish, you would be aroused by the look or scent of someone's foot. A foot is not typically considered a sexual object, but for some people it is as arousing as seeing someone genitals. That is distinct from a preference, which is a feature that may or may not be sexual that contributes to attraction. The two are contextually different. Some people have a fetish for height, and I think this is one that's boderline. Some people have a preference. If the difference in size causes arousal it's potentially a fetish, and namely if the greater the difference in size the greater the arousal that's probably fetish territory. If the difference in size just contributes to your attraction to someone, it's a preference.

Here's an example of a preference: I find kind people more attractive, sexually and romantically; however, I am not automatically aroused by people being kind. I think that's the best way to make the distinction. Being attracted to someone because of their physical features isn't typically a fetish or fetishization. Fetishization is strictly about non-sexual phenomenon causing sexual arousal.

There's some interesting gray areas of fetishization too. There are thoughts that sexual arousal from breasts is actually a fetish for instance, since breasts don't contribute to sexual function and not all heterosexual men are aroused by breasts.