<img src="large.jpg" lowsrc="tiny.jpg">

The lowsrc HTML attribute was an attempt to provide a low-resolution placeholder image while the main image was loading. And this made a lot of sense back when images could take 20 or 30 seconds to load on typical connections. But, even today, when network speed is relatively fast, this is still something that developers are doing, to provide their users with a better experience. A nice placeholder while the final images is loading. Certain sites load tons of images. Or operate in regions where fast network access isn't the norm. Or just because it's nicer this way. Now, the `lowsrc` attribute belonged to that end of the 90s period, and unfortunately didn't gain widespread adoption and was not included in the HMTL5 specification. But `lowsrc` didn't fail because image placeholders were a bad idea. It failed because the specific 1990s API never became a sufficiently well-defined, interoperable part of the web platform. The need didn't disappear just because this old solution did.