For this challenge we can download an image called "zipper_1_.jpg". I immediately think that might be probably a steganography challenge (Art of hiding data in image).
My first intention was to check the header of the image using exif tool on Linux. But it was unsuccessful.
I then thought that a file may have been bind to the image.
So, I used the tool binwalk to look into it.
We can see that a Zip archive has been detected in the image. Once extracted and opened we can see an .rtf file that contains the flag.