How to match randomly present picture from loop & merge?

Hi, I'm trying to design a two-stage game theory related survey question. So in the first stage, I used loop & merge to randomly present 1 portrait picture out of 8 photos (Showed as last two screenshots). But in the second stage, I would like to match the picture presented in the first stage, for example if in the first stage, No. 1 has been presented, then I would also like No.1 picture to be presented in the second stage.
I know branch if function could do it, but I have 8 picture in total, and 10 available decisions in the first stage, in this case I would have to add 80 additional blocks in the second stage, and 10 blocks for each photo. Therefore, I'm wondering is there any possible way to simplify this operation?