@Rafik molla, quite apart from the fact that the current cut is very recent and of a superior quality, this image didn't have constrain proportions ticked when it was resized, leading to the cut being stretched and looking unrealistic.

I recommend using remove.bg for your cuts. It's a fantastic free online tool which does the heavy lifting for you by removing the background in the source image, leaving you to only rotate, crop and/or nudge the collar upwards. It's tremendously easy to use and provides fantastic quality. With it, you can go from source to cut in a couple of minutes for the vast majority of images. 

Take a look at this thread for guidelines for cutters and video tutorials for some more info on what we expect for from our cuts. 

Here's a couple of videos on how to use remove.bg, one when combined with Photoshop and another using photopea.com, which is a free online app so close to Photoshop that it has the same shortcuts, layout and icons 😉 If you don't have Photoshop, photopea.com is the tool I would recommend to use to tweak the draft cut produced by remove.bg. It's more powerful and versatile than GIMP and other similar tools.