agile - Which swim lane should i move a task into when a task is done but new designs come in -

this overall methodology agile question .

if devs have completed tickets , qa team has moved them done .

if new creatives come in existing tickets best way handle .

my thought move them "to-do" , start them on ...

assuming using scrum usual start new ticket in situation. reason count points in 'done' , use total calculate velocity of team. if new story added need count work done , new work.

i expect questions asked in retrospective timing of new creatives. may have been better not have started on original story until new creatives in.