Why we have different indexes options inside 2 document libraries on our sharepoint online

Question

I am facing this weird issue inside our sharepoint online tenant:-

1. I have a classic team site collection, which contain 2 docuemnt libraries inside 2 separate sub-sites.
2. the document libraries are using the defualt content type.

3. now i wanted to add indexes for these document libraries (So i went to the document library settings >> Indexes >> Create), but i have noted that the indexes' options inside these 2 document libraries are different, as follow:-

   • inside the first document library i got these indexes:-

   • while on the second document library i got these indexes (where indexes such as MediaServiceAutoTags & MediaServiceLocation are missing):-

so can anyone advice why i got these differences? although the 2 document libraries have the same structure...

and second question which is less important, what do these 2 indexes MediaServiceAutoTags & MediaServiceLocation represent and how we can populate their values inside the documents ?

Answer 1

The fields MediaService*** are related to Image Analysis functionality. SharePoint o365 automatically analyse the image and update these columns example the location MediaServiceLocation. They are metadata columns related to an image.