Ascii art in HTML comments - fad or function?

Actually, I really like this. Of course it's "useless", and it consumes some bandwidth. But maybe it also generates some traffic, as people notice this and show it to each other. It's funny and can be understood by anyone, but still smells of engineering.

Maybe this is a step towards more people appreciating the beauty of our creations and "materials", the same way a lot of people appreciate nice (and useless) detailing on car engines, watch movements and bridges without really knowing anything about the inner workings? I certainly hope so :)

Adding this art to the file increases the size of each HTML download, which could equate to actual bandwidth cost increases on popular sites.

You already answered your own question. It is Art! It is not supposed (or at least, it is not required) to have mundane functional value. :)

Seriously: as far I know, it has zero technical justification. It's all about decoration, and an insider's way of leaving a mark (after all, most people are not going to look into the markup). It's also fine: In times where DSL speeds are the norm in many target markets, the "bandwidth" argument is mostly a weak one. Every family photo you download weighs dozens, hundreds or thousands of times more.

The only useful use of ASCII art in HTML that I know of is using it as padding for 404 pages to prevent some browsers from showing their standard error page.