Remaster or remake?
I think it's a remake, as yes, they did call it an enhanced version, but they also called that for the TTYD remake, and that's called a remake. I mean, just look at this image and tell me if there is a clear difference. I think, at worst, it's a remaster with updated models, and at best, it's a remake. There are also major changes, like accommodating the usage of only one display compared to two. Also note that not all remakes are built from the ground-up: OOt3D and MM3D were built with the original source code, and it is very likely that this game was as well, but is still technically a remake due to improved models. Altendo 05:53, September 15, 2023 (EDT)
I think it’s a remake. I looked at the image and the models of Luigi are vastly different. Around the time of Super Mario Odyssey, Super Mario Party, and other games from that era, Mario and Luigi started getting more detailed/realistic overalls and hair, among with other differences. Besides, isn’t Luigi’s Mansion (3DS) a remake of the original game? Yeah, and some remakes have just improved code and models.
Yes indeed, it is a meaningful difference! Even just look at Luigi’s pose, it’s more expressive. The 3DS image looks more like a “Wait-wha?!” Luigi pose while the NS one looks like “OH DANG THAT’S A GHOST!” Luigi pose. In other words, Luigi looks more scared in the remake. I’m gonna say this again, but isn’t Luigi’s Mansion (3DS) a remake of the original game? 
Wonder Time!