The following are all "official" images released by Er Gen. Please note that these images DO CONTAIN SPOILERS for anyone not currently up to the most recent live chapters!
An early promotional image before the novel was even launched, depicting Bai Xiaochun
Promotional splash image used later on, I think on Qidian and also on Er Gen's official WeChat
Original official novel cover art as used on Qidian for the first few hundred chapters
Second official novel cover adopted a few hundred chapters in, and used until the end of the novel.
Depiction of Hou Xiaomei, released on Er Gen's official WeChat
Depiction of Zhou Xinqi, released on Er Gen's official WeChat
Depiction of Du Lingfei, released on Er Gen's official WeChat
Depiction of Song Que, released on Er Gen's official WeChat
Depiction of Zhou Zimo, Mistress Red-Dust, released on Er Gen's official WeChat
Depiction of Bai Hao becoming Bai Xiaochun's apprentice, released on Er Gen's official WeChat