[antonvs]

The only ASCII image I see on that page is actually a PNG:

https://tuananh.net/img/buildkit-llb.png

Maybe the page was changed? If you're just talking about the gaps between lines, that's just the line height in whatever source was used to render the image, which doesn't say much about AI either way.

[tuananh]

looks fine to me but since it messed up for some so i replace it with png