A long expression that specifies the flags how the image is to be handled.
The Flag can be one of the following:
4 - Used to ask the object to use the supplied aspect ratio
32 - Used to tell the object to render as if for the screen
512 - higher quality image is requested. For example, if the file is 2000x2000 pixels but the embedded thumbnail is only 100x100 pixels and the user does not set this flag, yet requests a 1000x1000 pixel thumbnail,
it always returns the 100x100 pixel thumbnail.
