Contextual search logic?

I notice that when selecting search from any of the main screens (Overview, Artists, etc) a list of my previous searches are visible. When I am in the search results page after searching for an artist and select search again, I notice the previous searches are replaced by what looks like contextual options that Roon thinks is the most likely follow up. For example, if I do a search on Van Morrision then select search again the list shows some of his albums. If I do a search on the artist Sia whom I only have 1 album for, then select search again the list list shows the 1 album and some other artists with “sia” in their name.

So my question is, what is logic for the contextual search options after the initial artist search?