Is it clear?

[reverb]

It looks easy to me (but, then, I was there!). Can you tell me what and why like this?

 

[thelps]

the dark blob on the right looks like someone walking down the street.
The wavy white lines street lights.

I'm going to go with - the inside of a mixing bowl while making a cake?

 

[reverb]

Oh, how I wish your second answer was the right one! But, yes, street scene, long shutter time, early evening. I was trying to get a blurred image that moved the figures sideways, but failed completely. However, I did quite like the result anyway!