I love this piece of advice because I've never really been into describing troop movements although I did that once when I was starting out and wrote a regency that almost jumped on the historical regency bandwagon. Looking back on it, it had major problems starting with weird set pieces, and ending with too much exposition. It also had me detailing the entire battle of Salamanca with one of the Greenhill military books in hand. Total lack of focus, lol.
But anyway, this is cool. Resonance is a great word for what is actually a series of connections we make as readers. e.g. If there is no child, but there is a pair of burnt up children's socks lying on the road, and a war going on, then there is a severely injured or dead child as a result of that war. I told my kid once that the problems with this writing tool, which is also known as subtext, is that some people just can't understand subtext. Ever left a comment on a news article and had to explain you were being sarcastic? Yeah, same thing, right down to having to post a definition of sarcasm with a wikipedia link.
But when it works? It works wonders.