Context: Fukuda Shinta 福田真太 warns fellow manga artist Niizuma Eiji 新妻エイジ.
Niidzuma-kun wa puro toshite no jikaku ga nasa-sugiru 新妻くんはプロとしての自覚がなさ過ぎる Niizuma-kun, [you] lack self-awareness as a professional too much. (literally.) (double subject construction.)
You don't seem very aware that you're supposed to be a professional, you don't act as such.
{jibun ga tanoshiku kakitai} dakenaradoujinshidemo kaitereba ii 自分が楽しくて描きたいだけなら同人誌でも書いてればいい If [you] only {want to draw having fun} then [you] should just draw a doujinshi.
shikashi {"Janpu" de kaku} puro nanda しかし「ジャンプ」で描くプロなんだ But [you] are a professional [who] {draws at Jump}.
{dokusha wo tanoshimaseru} koto wo dai-ichi ni kangaenakereba dame da 読者を楽しませる事を第一に考えなければダメだ [You] have to make {entertaining readers} the number one [priority].
In other words, a doujin draws doujinshi to entertain to entertain themselves, while a professional draws manga to entertain the audience.
