I've cloned a repository from Github (same occurred from Bitbucket too).
After cloning, strange changes are generated. - non-discardable files.
After cloning, mack.jpg and thumb_mack.jpg are displayed as changed.

When I discard the files, Mack.jpg and thumb_Mack.jpg are displayed this time.

And if I discard again, this happens again and again - repeating.
This happens on other branches too - I've staged these files and moved to another branch, but the same.
I really don't want to add a new commit for this.
Please help me. Is there anyone who knows why this is happening?