On request from (and in response to) somebody on reddit, I'll show and explain the changes.
These are the differences on the "less visible" changed tiles. The new tiles are on the left, the old ones are on the right. As always lately, the difference is only a few pixels.
The '1/2' tile doesn't appear in the game at all, unless the wiki is wrong. I fixed it up all the same.
The '1/4' tile was too "small" before. It's always used as a sort of branch or root in the game. Even roc nests are, I presume, made out of branches. Making the slash longer helps fill out those tiles more and make them look more like branches. Incidentally, if there's any tile in the tileset where I'd want to break with my habit of making "improved default tiles" its here, as there's no need for this to be a fraction. Still, I do like how it looks now, so there's no point in breaking with tradition.
The '#' tile was connected to the left and right edges previously. Now it isn't. This made anything in the game that used these in a grid tile oddly, because the grates would be connected horizontally but not vertically. You can see this easily in the bottom-right corner of the combat arena, down a few levels.
The "new sky" is visible in a screenshot below:
Compare with the "old sky" below:
It gives a much nicer "illusion of depth". I didn't invent this trick. My current setting ([SKY:250:8:0:0]) was taken from Crazy 8x8, but it didn't originate there, either. The old setting is still there in d_init.txt, so it's easy to change it back. (Or you can just not copy over my d_init.txt).
Finally, because the new changes were indeed a little controversial (to at least one person), I'll explain them.
Dwarf tiles with beards had been bothering me, and I'd been making similar changes to my own tilesets. Dwarven women don't have beards, after all. I hadn't included this change in my main tileset because I felt people would miss the old tiles. I compromised by making the "oneshots" folder, and I can take reasonable requests for new graphics or tilesets.
The "designation tile" grid, for lack of a better term, does make things look "blockier" in some cases. The old solid colour makes it
really hard to see at a glance whether a room I've laid out to mine is 8x2 or 7x2, however, and my previous solution was always just to count them myself by hitting the direction keys. This is a little silly, because with a grid you can just count them visually off of the screen.
Hopefully that explains the changes! The same person mentioned a "new direction" for my tileset, but this whole update only changes 6 tiles -- and half of those by only 4 pixels each. There's no "new direction", and I'm not likely to make any more changes for a while.