iPhone 7 plus on IOS 11.2

i just found out that my iPhone doesn't make anymore the sound when i took a screenshot, the thumbnail doesn't appear in the lower left of the screen, but i can still find the picture in the library.

I don't know if it's a new feature of 11.2 but it was very nice to get the thumbnail to directly access to the modify program.

any clue?

Thanks!!

Marco