Screenshots within questions or answers are disfavored because their content isn't indexed. That makes good sense.
In my answer to this question, I nevertheless included screenshots of two charts, as the charts' size and content made using the quotation mark composition tool unworkable. When I returned to the question the next day, I found that the answer had been amended to successfully include the charts' information in an apparently searchable fashion. This was clearly an improvement to my answer.
I didn't know that was possible. How does one do this?