Interesting. I rarely have honey hanging around in jars for long enough for it to granulate - let alone frost. However, I have been holding back a couple of jars of horse chestnut honey from last year's spring crop, to enter into a show this year, in the set category.
Imagine my horror therefore when I saw they had frosted recently. Not as badly as the one at the top of your pic, but similar to the others.
With nothing to lose (and not wanting to reliquefy the honey), I figured a sharp blast of heat energy to the outer layer might be worth a shot, and the microwave was screaming out to me.
I removed the lids and gave each a quick 25 to 30 second blast at 900W. Cleared it for me. I can't warranty it will work for everyone.