I find this a complex question, and like others, think it has the element of individuality.
It took me a long time to realize i have a sub nature and i think that is largely due to how it is manifest. i experienced a lot of bullying growing up and to this day have an almost violent aversion to bullies and bullying.
It wasn't till the last few years that i was able to connect much of my bullying experience as a kid to the fact that i had a sub nature even as a kid that seemed to naturally attract kids with dom natures. When i look back at experiences that happened even as young as 6 or 7 years old, i can see how those experiences could have been early D/s experiences. Unsophisticated and ignorant kids exercising and discovering who and how they are. Nowadays, i see bullies as immature people who haven't figured out more intricate ways of Dominating (note: i'm not stating that as an absolute 'truth,' just my point of view).
The most powerful Dom i've ever experienced seemed to both humiliate and embarrass me but there was never an ounce of bullying employed. He was teaching me how to perform oral on Him in an awkward and difficult way. He never forced me and was extremely patient, though persistent. His method was completely encouraging. The embarrassment/humiliation part was how He addressed me. He spoke to me continuously and encouragingly, almost like He was teaching a child or a puppy how to do something. His attitude was really over the top. When i'd do something He the way He was instructing and liked, He'd literally gush: "Good boy!!! I'm so proud of you, aren't you proud?" i could feel my face go red with embarrassment, and strangely, pride.
He nailed it, and He knew it and it was sort of humiliating to be under His power that way, but the key (for me) was His total affection. We both knew He was totally Domming me, but His affectionate way totally opened me up and the end result was He evoked adoration in me for Him. Adoration is not something i have felt with anyone else, but He managed to elicit that response, and the thought and feel of it is both intoxicating and embarrassing, maybe humiliating?