That is awkward, DrBB. You don’t want to fail to acknowledge the consideration extended to you. Yet you know that the choice made by your coworker/friend/relative does not work well for your BGs.
You’re then faced with gently giving them the bad news about their choice or just go along get along, suck it up, eat the “thoughtful” food and try to reel in the BGs later.
That’s not a good choice either, since that person will do that again thinking their choice is a good one. Perhaps the best way is to use that situation to discreetly explain why their idea of safe food for you is not really safe.
Have some good replacement suggestions in mind like nuts or cheese or sweet dips that can be portion controlled by the diabetic. Some of us can even enjoy a scoop of full-fat vanilla ice cream from tme to time. (Finding full fat ice cream can be a challenge.) I’ll take mine with berries on top!