So I have looked through as many old articles as possible before posting this question. Hopefully you can help.
If you have a site, say 5+ years old. This site has at least 10 million product pages that is well known and normally well ranked within the search results. If all conventional rules are follow as listed below. Why would the site not rank?
1). Appropriately named image file. 2). ALT text that matches such an image file and "is appropriately placed within the content of the page including the title". 3). Image loads very quickly.
Additional context, this site also has affiliates who use the same image servers to display images on their own sites. Some, however not all of these images show up for "particular" affiliates. These sites are not as near old or powerful as the primary site.
Can anyone provide possible solutions for this problem?
Hotlinked images often seem to cause problems in Image Search for the original domain - I'm not sure why, but thee have been several reports about this here. Have you checked results by turning off SafeSearch filtering in your Google preferences?
Also note, the site: operator does work in Google Image Search. That might help you research the issue.