Ha I think I’ve watched a video of someone do that once. No idea why.
Log slices as chair seats is a lovely idea but I think Beth is right, they will probably split after they’re sliced, when the cut surfaces start drying out. It might reduce the chance of them splitting if you do quite thick slices? Not sure. But once they’ve finished drying and have settled down again you could fill the splits with something that contrasts and put a butterfly or two in them to make the split into a feature.