I just like the term, I want to share it with you and since I thought it up, I want to say it like this: criticism on toast(TM).
You've had praise sandwiches, we all have. If you've just read the worst script imaginable, and you're obligated to comment helpfully, you find a few good things to say at the top, a few good ones to leave to the bottom, and you try to make the filling in between helpful but thin. When the script is so bad that you just have to get out fast, you use a praise sandwich.
I've been sent many a sandwich. It shouldn't work: as soon as you read an opening line that goes "Your typing is immaculate", you know you're in trouble. Perhaps it's just me, and how I'm a sucker for being praised for my typing (oh, if you only knew I was serious there), but I read this opening line of death and I am simultaneously aware I'm in for a beating but also mollified.
Once I read a script so bad I had to go take a two-hour bath to think up something good to say about it for the bread in the praise sandwich. And I still failed. In the end, I made up something: I said the opening was just like XXXXXX and then I went on to praise XXXXXX for a paragraph instead.
But the other day I got my first of a brand new type of script report, a type I am going to call criticism on toast. Because it went straight in on this doesn't work, that doesn't work, what were you thinking here and this is rubbish. Then it ended with comments about great gags, it praised me on the way out. Without the slightest doubt, this praise at the end was as false as the praise I give at the top and bottom when I don't like something. But because it came last, I liked it and let myself believe it.
If I were cleverer, I'd have written this entry criticising you at the top and then building to the praise you so thoroughly deserve at the bottom. But I'm not, so I didn't.