A screenshot that doesn't show the modified properties of the layer in question is pretty useless because there are hundreds of thousands of possible things you could be doing in a comp that could cause problems. This looks like it could be motion blur or some kind of distortion effect but I can't say what could be going on. One possibility is that you have two copies of the layer or it is repeated and the anchor point of one layer is on the left edge of the layer and the scale is slightly different or they are in slightly different 3D space. Something like this could also be caused by different pixel aspect ratios in the footage. This could also be a cache problem so try purging all image and disk cache under the Edit>Purge menu.
To reveal the modified properties of a layer or layers just select them in the timeline and press the U key twice. Solo the layer first to make sure that another layer or copy of the layer is not causing problems. If the problem persists start digging into the layer properties. Look for effects and start turning them off until you find the problem. If that doesn't help then look for keyframes and other things that may be influencing the layer. If the layer giving you problems is a nested comp (pre-comp) then you will have to open up that comp and dig into it as well. If the problem is not in the layer then maybe it's in the footage. Any footage item, including a PNG can be opened in the footage panel by double clicking on it in the Project Panel. Look there and see what's going on. You should be able to drill down far enough to get the layer into it's default position with no effects and see a normal image.
If you still don't have an answer then post your findings and assumptions so far.