Got it. My issues were – a) Png files were not visible b) jpg images were appearing broken. For problem a) I replaced png files by Jpg files. For b) What I found is that the images if uploading from a redirected URL failing to render in Media Library. For example I stored images in a sundomain and created a redirection to it in server. Under such scenario the media library Php for add/edit image was not finding the image. So now I created two copies – one in so-content/uploads and the other in the redirected URL. Now media library can find my images. So after editing in wo-content/uploads I then manually move the final image to the mapped directory.
To be sure I changed the image file permissions in both directories to 644. Thank you all for your help
