XCUIElement not found using app.images when running XCUITest - objective-c

Question

I have a a XCUITest that fails to find a specific image, yet it is perfectly visible on the screen.(emulators and physical devices)
How can I workaround or make the the UIImage accessible to the tests?
All I want to validate is whether the element is visible and touchable on the screen.
The UIImage is added as a subview to a UITableView - it is placed at the bottom of the TableView.
- (void)viewDidLoad {
[super viewDidLoad];
// portions of code left out here
_aView = [[UIImageView alloc] initWithFrame:CGRectZero];
[[self aView] setContentMode:UIViewContentModeScaleAspectFit];
[[self aView] setImage:[UIImage imageNamed:IMG_NAME]] ;
[[self tableView] addSubview:[self aView]];
The UIImageView is later layed out:
- (void) viewWillLayoutSubviews {
// portions of code left out here
[[self aView] setFrame:CGRectMake(0, MAX([self tableView].contentSize.height - 41 ,[self tableView].bounds.size.height - 41) , 180, 30)];
[[self aView] setCenter:CGPointMake([self tableView].center.x, [self aView].center.y)];
Then when running the test:
let app = XCUIApplication()
//this works
let tapString = localizedString("skip")
let skipButton = app.buttons[tapString].firstMatch
if (skipButton.exists) {
skipButton.tap()
}
let theImage = app.images["img.png"]
let doesExist = theImage.exists //<< it never exists
Also doing a debug and printing all the images
does not show the image. I set a breakpoint at the line with doesExists
and in the debug window I run the command:
po app.images
Many images are found but not the particular image under test.
Is there perhaps an alternative to solve this problem?