Setting aside the programmed randomness in a game/editor/engine, it's very much based on the skill of the level designer/environmental artist to be able to handle vast void spaces which might look boring and transform them (if needed(!)) into something more interesting to the eye.
I myself kinda work in segmented randomness if one can say that, where I would make a base, a basic tileset and then scatter small and larger details in some places more than others, so it won't look too even and "generated".
Here's a scene with an obelisk and a few items, just sitting out in the vast desert, one tileset, that consists of 3 images, completely random. What I do then is that I add a bunch of stones, some dried up grass and dunes, combined with a more blank desert tile, one should also know, that the small stones have 7 variations to them, one being "no stone" so, even if they are manually placed on the ground, they might not show up or might create what looks like, very random but still organized patterns.
If I were to zoom this image out, you might find that this pattern with the dunes probably don't repeat, some ares might be very low populated with stones and dunes and some might be more dense.
Here's another example, but more focused on a smaller area, all the lupines you see here are like the small stones in the previous image, they have a few variations and one is "nothing", what I've done is that I placed tons of them by the corner to give out the feeling that "for some reason there are just more flowers here", there really is not reason, except for making the player think that.
To answer your question about the scene you posted, if I can do nothing else but to rearrange, I would (if the engine allowed me) move some of the flowers to the foreground, so that the player walks behind them sometimes.