The clipboard can represent an image in two different ways:
1) as a DataFormat.FILES entry : it happens when the user select a file
   image on his desktop and copy it
2) as a DataFormat.IMAGE entry : it happens when the user select a portion
   of Image with his preferred image editor and copy it

SB knows how to paste the first type of entry.
It does not support the second type : since the image data have representation
on the file system, it's not possible to create an ImageView + Image directly.

One improvement of the Paste command could be this:
when the Paste command detects an DataFormat.IMAGE entry (i.e. type #2 above),
it could display a dialog that explains that image data must be saved first
and propose a "Save As" button.