When I visit steemd.com, I found that every user have different avatar on that site.
So I try to find out how it's work, and eventually got it.

@abit

@abit is one of the big whales.
First, let's give him a close-up!
A little evil，right?

How to check your avatar?

To check your avatar is very easy, just change oflyhigh to your steemit ID.
https://robohash.org/oflyhigh.png?size=256x256

The avatar of active authors under the CN category

ID	avatar
@abc1621043211
@abc521
@ace108
@anwenbaumeister
@bestmz
@btshuang
@catcat
@cctvsmg
@changkun
@chinadaily
@cindyan
@cnfund
@cristinabu1990
@dabaisha
@dianailuma
@elfkitchen
@feelapi
@fishingvideos
@fundurian
@hilarious
@i603
@jademont
@jamonchina
@jianghao
@konstantin
@kyleb15
@laonie1
@laonie
@lemooljiang
@lyj
@macartem
@mayyangtaiwan
@mrlee
@myfirst
@oflyhigh
@ola1
@rea
@richardjuckes
@rivalhw
@scientihark
@sophiachan
@steemitjorya
@steven1980
@sweetsssj
@theflowers
@thornybastard
@wuyueling
@xiangni
@xianjun
@xiaokongcom
@yangyang

So include your avatar in every post you made, let every one remember you.
And you can go Robohash.org to find more details.
Enjoy It.