1. An image display apparatus comprising: at least one processor or circuit configured to perform the operations of the following units: a display unit configured to simultaneously display first image data corresponding to reconstructable image data included in a first image file and second image data corresponding to non-reconstructable image data included in a second file on a display; an acquisition unit configured to acquire the first image file that includes the reconstructable image data that includes information corresponding to a light field and the second image file includes the non-reconstructable image data; a generation unit configured to generate a plurality of images having different focus positions from the first image data; and a control unit configured to control the display unit to perform display for informing a user that the displayed image data corresponds to either the first image data corresponding to the first image file or the second image data corresponding to the second image file, and configured to determine whether the image to be displayed corresponds to reconstructable image data, wherein the control unit informs a user that the displayed image data corresponds to the first image file by causing the display unit to alternately display the plurality of images having the different focus positions.