Prevent render blocking resizes

[indykoning]

We do not need the bounds because ResizeObserver passes devicePixelContentBoxSize along with the bounds, WITH dpi factored in!

Previously the eager loaded images are render blocking when downloading the new image:

Now by setting loading to lazy before, pushes those downloads to the background:

So your onload is much quicker.

Currently as draft, as in my current testing scenario i get a flash of white on my images while they load (Not impacting pagespeed might i add)

[indykoning]

The flash of white unfortunately seems impossible using conventional means. using the placeholder as background image ensures you don't notice the flash