Being out of the cult 15 years or so... I think the paradise pictures were, in general, carefully inclusive of all material fantasy of things not obtainable in the present ""Systems of Things"" (unbeknownst due to being under the thumb of the WTBS, under Derridean erasure). To wit, a child cannot pet a panda in actuality because the child is forbidden from getting higher education and some degree in veterinary science and going to exotic locations and getting a wash of oxytocin from engaging directly with fellow mammals. The adult can fantasize about, and more importantly covet, the 2000+ square foot house on the hill with the sweeping vista that raises the real estate value and the carefully cultivated garden that says real eating because the adult is forbidden from taking paths in life that lead to material benefits. The paradise pictures are like an officially sanctioned Two-Minutes Covet. Of course they all serve Jah because they want to of course. Not for anything resembling a supply and demand curve.
And buttressing this coherent, rifled covetousness into an indeterminate future is the sanction against learning enough science to recognize what "eternity" and "everlasting" mean in quantifiable terms. I bet every single JW has enough brain cells to question the silliness and unfoundedness of the Everlasting Paradise Earth reward / motivation / sky cake / goal / prize.
By way of irony, the JW cosmology has the earth only being built 6000 years ago {someone now claims no, it's not a literal thousand years per day...?} when the science has our surroundings going back 13.5 billion years, and the JW is expected to make a decision about |Eternity| based on a world context of ~6000 thousand years. This 'ontogeny recapitulates the phylogeny' that JW young are expected to (have their parents force them to) consider getting get baptized at <10 and maybe around 5yo.
The closest thing to JW Paradise paintings (dreamy, surreal, won't-happen) that I have seen are the depictions of a Stanford Torus by Don Davis from the 70's.
http://www.donaldedavis.com/BIGPUB/STANTRUS.jpg