Certain cards don’t return gold images for all the supported locales. I’ve seen instances where 1 locale’s gold image is available, 3 locales, 4 locales, and sometimes no gold images at all.
The below cards only return a gold image for en_US. If you fetch these card for a different locale, for example de_DE, it will still return the gold image for en_US.
The below cards have no gold images:
The below cards have 3 locale’s gold images:
The below cards have 4 locale’s gold images:
In addition to the above inconsistencies, it seems that cards that are available in both standard and battlegrounds return the battlegrounds golden image instead of the regular golden image. This card for example:
Note: These are only some of the examples. There are many more.