Pasted image not visible

[Yash Pal]

I copied and pasted a part of an image in the same image, after extending the canvas size to accommodate the pasted part - the background of the image was made transparent. The pasted image is not visible, though the marching ants of the selection are seen. I changed the background to white, (new layer - white; and put the white layer below the existing layer, but still the pasted layer cannot be seen (not visible).

I am making some mistake but do not know it. Can someone please tell me how to make the pasted layer visible?

OS: Ubuntu 14.04; GIMP: The version available in Ubuntu Software Centre (2.8.18)

 I had asked this question in another forum; so far, there is no reply.