> progressive jpeg

That's a thing? I didn't know you could do that on purpose thought it was a side effect of slow internet.

I've used CSS blurring before/loading different sized images but I think this is different when reading up on it.

Yes, it is a thing: https://calendar.perfplanet.com/2012/progressive-jpegs-a-new.... Some people do use it intentionally.

>That's a thing? I didn't know you could do that on purpose thought it was a side effect of slow internet.

Well if you don't have it enabled, the area that is shown would be proportional to how much you have loaded (eg. if you have 50% of the picture downloaded then the top half of the picture will be shown, but the other half would be blank/transparent). If you have it enabled, then you might have the whole picture shown at 5% downloaded, but it will be super blurry, and as you download more it gets progressively more detailed.

I don't think the author/publisher purposely used this as an effect, it's just an overloaded server and whatever image editing software he used had progressive jpeg enabled.

Yeah that's interesting good to know

It's designed specifically for slow internet speeds. After ADSL type of speeds became the norm, the use progressively loading images slowly faded away.