Modelling Technique Question I'm following a time lapse clip which has to do modelling the PLayStation 5.
I cant seem to understand what the modeller is doing at 0:20 seconds,(I lowered the speed at 0.25) Somehow he is avoid a tri face. But If I continue modelling, as seen from the different angles I've provided I'll get a tri face in the corner of my model. Can someone please tell me what he's doing with the mesh to get a quad when he extrudes the mesh.

Thank you.

https://www.youtube.com/watch?v=WzGkQAfxakE&amp;list=LLZ2XZXqOZRx6idQLEh4-RIw&amp;index=2&amp;t=13s
In the video he had some hesitations but at some step the result is simply to merge two vertices.

In vertex selection mode Ctrl1, 

Select the vertex on the left, then Shift select the other one.

Then merge them using AltM then 'At last'.

The model is more or less in this situation: