12-lead EKG

I'm trying to understand the time frame of a regular 12-lead ECG. Please look at the image I posted. Does I, II, III, aVR, aVF, aVL, V1 to V6 represent the same "heart beats"? I was told in class that all vertically aligned QRS complexes represent the same heart beats. If that is true, then since we have a longer V1 on the bottom, does that mean all the leads were not taken simultaneously? I'm lost please ELI5 this to me.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums