You already got good answers on the color side, so I’ll add something slightly different.
When we resurfaced ours, I thought the same thing. It wasn’t just the darker finish, it was the new tile band and coping. The old setup had kind of soft, faded edges. After remodel, the waterline tile was crisp and the coping had a sharp contrast, so the boundary between water and deck was way more defined. That clean outline made the pool feel more “contained,” if that makes sense.
Water level can play tricks too. After startup, I was keeping the water a touch lower while dialing in skimmer performance and watching filter pressure during the first couple weeks of plaster dust cleanup. Even half an inch lower than you’re used to changes the visual proportion of tile to water and can make it feel smaller.
Also, super clear water changes depth perception. Once chemistry is balanced and there’s no haze, you can see the floor slope and break lines much more clearly. Your brain reads those transitions differently than when things were slightly dull or mottled.
Give it a few weeks. Most people stop noticing once furniture is back, landscaping settles, and you’re actually swimming instead of analyzing it. Has anything else around the pool changed, like deck color or furniture layout? Sometimes that’s the sneaky culprit.