There's huge style conflictions.
Modernistic metallic exterior is clearly a time machine, because once you step in the base you're in a 1950s Mafia style base.
These mafia types, however, are much more refined than most gangs. They seem to be more concerned with decorating the place with plant life and couches than actually fighting. That's something I've never quite understood. I guess you're sitting there making the level thinking "how can I add some decorations?", but the best thing you can come up with is plants? I really doubt too many gangs or mafias dedicated their bases as part-time greenhouses. I definitely may be wrong about this, but I feel like the "decorations" would have been more in line with bags of what seems to be flour, firearms, knives, explosives, and centerfolds. Granted, you can't put all of that in a game that allows (and seems to almost be entirely played by) 13 year olds, but you get the idea.
I think you could get much more creative than plants.
And let's talk about the decorating style...
Here we see that Black Holst is very multi-cultural, sporting Bonsai plants in addition to generic-potted-plant-that-has-been-around-since-the-beginning-of-era.
There's two Bonsai. Lined up in perfect unison. You don't get that kind of symmetry in nature often, much less in a gang base. That's just not even close to realistic. If you HAD two bonsai, you wouldn't stack them directly together, especially IF they're the exact same bloody bonsai.
And they're also concerned about plant's comfort, dedicating what appears to be small chairs so the two potted plants can sit comfortably. I guess because they're so old, over-used, and tired, they can't stand on their own anymore. Note again them being lined up perfectly well together. That kind of stuff happens everywhere, I just refuse to waste the time to gather up a bunch of screenshots to belabor the point. Go look for yourself, it's impossible to miss.
And do I even need to mention the mini-space-station sized elevator? Complete with, yes, plants, couches, and even a table with some refreshments in case the elevator gets stuck. Best part though? They somehow figured out how to create automatic sliding WOODEN doors.
Bravo.