That and the smell of opening a new vinyl album ..
And things like In through the Out Door with different covers and the (hidden) water paint aspect <grin>
If you got the sleeve damp it gained color ..
Wikipedia -
"The original album featured an unusual gimmick: the album had an outer sleeve which was made to look like a plain brown paper bag (reminiscent of similarly packaged bootleg album sleeves with the title rubber-stamped on it), and the inner sleeve featured black and white line artwork which, if washed with water, would become permanently fully colored. There were also six different sleeves featuring a different pair of photos ..."

A lot of work went into some of the packaging alone.
I was also a fan of some bands that used real artists for covers, like some of the Yes albums.

I do not work here, but the benefits are still awesome
Make your sound your own!