I was wondering why my Particle System looked differently and with quite a bit of comparing the two I managed to find out why.
On my Particle System, the X axis rotation was by default set to -90°.
I watched the start again wondering why that had been omitted from the video, but in there the Particle System that gets added has the rotation values all at zero right from the start when it was added.
Changing this fixed my Partcle System’s appearance to match the video.
(In between I had set the X axis rotation for the shape to 90° but I wondered why this should be any different, so I dug deeper)…
So whatever the reason for the difference (maybe because I started to add it inside the prefab right from the start), it would be good to add a bit to point out the transform settings on the Particle System as well.