lol....I thought the text might have been it but I was looking for filtering, tones, etc....lol. Way to overlook, and overthink. Gee.
The difference in the first two is very subtle and I thought vignetting had to do with blurring the edges...see? I don't read well...or see well. Getting so old. It's good for a laugh at any rate.
There is so much to see and read on here, that we are all guilty of skim reading! LOL!
You can create a blur type vignette too, so you were not wrong at all! And you did get my point that I preferred subtle vignetting. LOL! With subtle vignetting you don't so much see the vignetting as you see the center more clearly because there is a little more contrast. If you go back and look at Number 2, you may notice that the area around the flower appears lighter - although it is not. It's the outside edges that are darker. :-)
Oh yes...I see it. Mind tricks. Optical illusions and whatnot. It's interesting how the brain processes what the eyes see.
It is interesting, I agree!