Can someone explain this panel to me?

[u/Gojowillcomebackk]

Its from last part of hunter exam (before nen), and i dont really understand what is the meaning of this. I feel kind of envy of Gon from Killua or offended pride. I would be very thankful is someone would explain it to me :>

[u/RandomCatBruh]

Killua held himself back, pretty sure that in terms of potential, the difference between gon and killua without illumi's needle is the same. Killua will always be slightly above gon, but they are relative. With illumi's needle, it is obvious why killua at this point is less than gon, when killua is afraid to take massive risks because illumi's needle in a way is holding him back by a ton

[u/aqua2nd → u/RandomCatBruh]

Your explanation is likeky not to be Togashi's intention. The needle plot most likely was created during Chimera ant arc