I don't want to sound crotchety or mean but I think the close trim option is one of those options that just ruins the boots for me. I feel like a huge part of what makes a pair of White's look like White's is the double row of stitching.
I feel like close trim, block heel, lowered heel just takes all the mojo out of the boots. So I prefer to leave the boots as close to standard as possible.
*** this really has nothing to do with the question asked about "what close trim means" but is just something I was thinking about since close trim was brought up. Also not meant to put anyone down for owning boots with close trim, lowered heels, or block heels - to each his own. ***