Need help with double-stim n-back in Brain Workshop

[BM XT]

So. To start n-back again after long break I decided to make it less boring by using meme pics. 

Also I want to practice double and sometimes in the future triple stim (2 or 3 pics simultaneously).

But I ran into a problem. I can't distinguish between what brain workshop calls vis1 and vis2 (visual stimulus one and two) and position also. Intuitively I thought vis1 supposed to be the left 1 and vis2 is supposed to be the right one. But it seems that I\m wrong.

Is there any pattern between how Brain Workshop names each stimulus?