These puzzles are almost always from designer Raf Peeters, who is credited with the subject of this post: Castle Logix, which debuted in 2007 and which is still on the market today. In Castle Logix, you are given four blocks and three towers with which to recreate 48 images in a challenge booklet. Here's an example of both puzzle and solution:
Castle Logix was originally released for players ages 5 and up, but current versions of the puzzle are labeled "3+" — which makes sense given that the blocks and towers are great to use as toys, even if the youngster has no capacity or willingness to solve the puzzles.
The puzzles are divided into four difficulty categories: use six components in a structure, use seven components in a structure, balance or finagle the pieces in some manner to recreate an unstable structure, and assemble a structure when given only an outline of it. My son, who is now 11, has tackled these puzzles on and off over the years, typically doing a few puzzles, then losing interest, then going back to it at some later date when I bring it off the shelf again. His attention span resembles a flighty bird for anything in which Dad has an interest...
An adult will likely find only the final quarter of challenges interesting as the outline challenges can be quite difficult — but should you solve the middle batch of puzzles, you'll likely find them easier to solve given that you'll see the various ways that blocks and towers can be integrated with one another, thereby giving you clues for how to fill in those outlines.
As for younger players, well, who knows? Depends on their tastes and the environment you've built for them. Maybe they'll just want to scoop all the bits into other blocks they own and play with them that way. Maybe they'll be as obsessive as I've been, solving all the puzzles in order every year or two, then packing the puzzle away until the next time. Those early challenges are easy, sure, but I still find it satisfying to plonk the blocks together, similar to writing a completed task on a "to do" list only to cross it off immediately. You did the thing, yes! Now what's next?