Yasuho had that idea from the first Johnny style shot in the previous chapter. Paisley Park stayed above Josuke the whole time waiting for an opportunity to use his birthmark bubbles on Tooru himself.
@shotalover69 Araki doesnt draw the birthmark on a lot of panels where it should be, i think he doesnt like to draw it in every panel, maybe he thinks it could get annoying and people already get that its there, or maybe its some AU shenanigans because i dont think Jojolion is going to end that straight foward with just a shot, we gonna go back in time or go to another universe or some shit like that i believe. And we gonna see how the mark got into Kira's wrist aswell.