What I see is that in the middle third of the photo, the entire image is duplicated a bit to the left of the main image.
I don't think this can be caused by any sort of lighting issue, because new light sources can't cause something to shift sideways (unless we're talking about two flash bulbs firing while the camera or subject is in motion, and even if that happened, the effect would not be limited to a horizontal band). Similarly any internal reflection inside the lens should exist for the entire duration of the shutter's motion, not just part of it.
If this effect were over the entire image, I would guess that you held the shutter button halfway down a little too long before taking the shot, and then shifted just far enough that the IS mechanism hit the end of its range and recentered itself during the shot.
However, because this occurs only over the middle section of the photo, that suggests that the photo was actually exposed twice (and you moved a bit between those exposures). This suggests to me that the second curtain is opening while the first curtain re-closes, and is briefly getting out ahead of the first curtain, meaning that the first curtain is moving too slowly. This must be a fairly slight mispositioning of the first curtain, as opposed to being truly stuck, or else part of the image would be massively overexposed.
If you are in a mode that shoots repeatedly, and if your camera has multiple speeds, slowing it down might change the behavior. Worth a try. Either way, I'm pretty sure you'll need to send the camera in for repairs. It likely either needs some sort of shutter adjustment/lubrication or a new shutter.