All minor arcana are illustrated. A curlicue of flowers around three cups is an illustration. But many of the modern ones are scenic.
I like quite a few scenic decks and use them regularly, but they are not as good for developing intuition and imagination as those decks without scenes on the minor arcana. Basically, scenes are the creator's own vision, imagination and intuition projected onto the arcana, and that directs one's own vision, imagination and intuition, instead of letting it run free as it can with non-scenic decks.
Just as I enjoy other people's stories and hearing their ideas, and taking them further in my own mind, I enjoy scenic decks. Just as I enjoy making up stories from basic elements and feeling the weather in the breath of the wind, I enjoy non-scenic decks. I learnt how to write poetry by imitating others' - but for my own poetry, I need to cut loose, I need the bare grammar and vocabulary of tarot without a pre-set storyline, and that's found in non-scenic decks.
To give a concrete example, with the 3 of Cups. If I look at three girls dancing, that limits my imagination and the possible meanings much more than if I see 3 Cups in a curlicue of flowers, which might be 3 cups for anything - joy or sadness, a party, a menage-à-trois, a business meeting in a pub, a spiritual communion, a church, a pyramid or a tetraktys, etc. Why limit my imagination to 3 girls dancing, when I can have so much more, and wider? The intuition too has to become that much sharper and more precise when you don't have the crutch of someone else's vision.
Basically, scenes on the pips are the training wheels of tarot, when it comes to using tarot for divination (if it is for meditation or for art creation or appreciation, that's another matter because there scenes play another function).