Are you referring to the Q&A feature within the PowerBI service with respect to Dashboards? Or are you referring to the Q&A Explorer within PowerBI Desktop?
If it's the first, you can pin visuals to a dashboard that are generated by the Q&A ("Ask a question about your data") feature.
If it's the second option (https://www.youtube.com/watch?v=RcQ8gE-1hSU), I don't believe the Q&A Explorer feature was designed as a mechanism to add visuals to a report. As you mentioned, this can be done easily with the "Ask a Question" feature, or by dragging fields onto a report manually. I believe you can only save "questions" that populate visuals into the Q&A Explorer. Again, I think the intention of this feature is more to guide consumers of reports to questions that might be frequently asked of the data that doesn't appear on the report itself.
