In the following tests the image filename is "banana.png" so if you hear "banana" as the alternative text this means that the assistive technology is using the filename because it isn't finding any other text to use. You should regard this as not passing the specific test.
The image below uses aria-labelledby and should indicate that "Van Gogh's oilpainting of sunflowers" is the value.
Van Gogh's oil painting of sunflowers hangs in Amsterdam's Van Gogh museum.
The value should be "4 of 5".
The image below uses aria-label="Sunflowers".
The value should be expressed as "The school of athens by Raphael".
This famous painting by Raphael is the artist’s most famous work.