Invalid Image – For iOS applications, icons included in the binary submission must be in the PNG format.
If your application supports the iPhone device family, you must include square icons of the following dimensions: 57×57 pixels and 120×120 pixels.
If your application supports the iPad device family, you must include square icons of the following dimensions: 72×72 pixels, 76×76 pixels and 152×152 pixels
via 9to5mac
