For functional, pendants, and nonfunctional carousels
Though swiping or using the arrow keys is the main way users would probably navigate through the images , fixing the left and right arrow buttons would be add an extra user friendly touch.
Currently, depending on the image size, the arrows get moved up or down as the carousel is scrolled through, which becomes somewhat annoying. In this case the arrows should always be in the same place.
On mobile, if users wants to go to the next or previous page, they have to scroll back to the middle of the page and click the arrow. In this case, the arrows should be fixed to the section visible to the user as they scroll.