To be honest for how competitive they were, the MCL38 was a rather boring car to look at compared to the other top teams. I guess it was the tightest around the sidepods? A side-view comparison with Ferrari shows this the best.
Other than that I suppose the suspension setup was also quite aggressive, both in the front and back. The front in particular had this peculiar assembly which hasn't been seen on competitors in recent times.
Craig explained it in a post earlier this season :
Genuinely can't think of other interesting things to mention about the car. The flexing stuff is hardly new and I don't consider it technically impressive. Looking forward to the "brave risk" ideas they mentioned for the 2025 car. Similar things were said about the MCL38 when it launched as well, naming multiple innovations in the car. When the car launched though, there was hardly anything screaming innovation on the surface so who knows what Andrea meant by that. There is a lot we can't see. Would be disappointing if they roll out with a MCL39 that looks largely the same with MCL38 in the flesh, but also not very surprising considering this is going to be the last year for these regulations.
Still, whatever the car has on the inside doesn't really change my point. The MCL38 last year was quite boring to look at.