I wonder if the word "background" caused misunderstanding:
Context: Well, I soon dug out the photo taken of Mr Chen and myself two years before, when I was interviewed by him as a reporter, and put it in the very middle of the bookshelf. The background of the photo was a wall, with a round quartz clock hanging there, which clearly showed the moment: 1:13:04PM, April 5, 2002.
What I wanted to express is "in the photo when it was taken, its background was a wall", not now where the photo is put (e.g. we put the photo on the table, so the background of the photo is the surface of the table. Is it possible that readers misunderstand "the background" as the place where it is put?