Series - Contains - Indirect

I was adding the books contained in this particular set and there are a number of books that say they are contained (they are not) and then (indirect) next to the title. What does this mean?https://www.librarything.com/work/17040643
Thanks

https://www.librarything.com/work/17040643

This set includes three books. The first book - Scattered Magic contains several stories. Those stories are listed as being contained in the set indirectly.

If they are not contained, then the Amazon listing is wrong.

Thanks, the light dawns!