I used to be on the opposite end of this phenomenon a lot in The Burning Crusade xpac of WoW.
I am a very old-school PVP warlock, I did my time in the old-school rank grind and as a result, I have something of a reputation on my server.
I am not good at very much; I am ugly, socially awkward and I cannot dance to save my mother's life.
However, I am very good at warlock.
So, TBC. Right at the beginning, there was this Tailoring set called Frozen Shadowweave, which quickly became notorious for it's at-the-time unheard of level of pure damage stats.
Also quickly notorious was that the chest piece of the set was a tunic instead of a robe. The set was universally reviled as looking fucking hideous, with Undead - like me - coming off looking especially stupid.
undead toons look awkward and ridiculous even in a robe, but out of the robe, in a pair of pants, we look like fucking hobos.
Now, my lock has always been a tailor, so naturally I made myself a set of FSW as soon as I possibly could.
In that set, with my sword and offhand, I looked exactly like a pathetically undergeared rogue.
I looked exactly like a pathetically undergeared rogue.
And absolutely nothing at all like an extremely experienced, arguably OP caster class wearing obscenely powerful gear.
People would approach me, regularly, in battlegrounds, as though I were a pathetically undergeared Rogue who did not know how to Stealth.
Essentially, they - and this was an extremely common occurrence in every BG I set foot in - would approach me as though they had absolutely no chance of losing and it was crazy obvious that they thought they had absolutely no chance of losing.
Seriously, I would have felt bad about the deception if not for how fucking incredibly cocky some of these assholes got.
I recall one warrior in particular, he ran around me in a circle, spammed /dance, /lol and /spit and then /chickened at me, apparently daring me to take the first shot.
Absolutely positive I could never possibly beat him.
Sadly for this man, it turned out that I was not a rogue, the word before my name was 'General', the pathetic-looking gear was some of the strongest in the game and I had over a hundred and sixty thousand lifetime kills' worth of experience in dealing with warriors.
As often occurs, this overconfidence ended very poorly for the warrior.
He left the game seconds after he hit the ground, leaving me barely enough time to /lol heartily at his corpse.
Good times.
And then, sadly, the FSW chestpiece was turned into a robe, I stopped looking like a pathetically undergeared rogue and people in BGs stopped offering their balls to me on a platter.