When Neeko is disguised she should be able to change back into herself without attacking.
This is currently how her Passive mechanic works, she can disguise as someone else but she must stay as them or switch to other champions until she attacks an enemy champion. In the image above there's an extra space. Riot should add Neeko into the extra space. It would enhance her trickery and make her passive more useful.
An example is that a Neeko turns into a toplane fighter for the extra base movespeed to get to lane and she cant transform back without using her Q or E. It is disadvantageous because it makes enemies more aware of your playstyle and is awkward in lane. When I turn into Aatrox to run faster and then I have to arrive in lane as him, the enemies obviously know that Im Neeko and the trickery is ruined. I have to awkwardly stand in the lane as Aatrox until I use my Q or E again. It feels embarrassing for the Neeko in a way.
tl;dr As Neeko you want to be constantly using your passive but not letting your enemies know that you are until you strike, not being able to switch out without using Q or E ruins her trickery and is awkward because it breaks the illusion.