As well as this, the sides seem to be smoother, making it easier to fit into your pocket. This corroborates previous reports.
And as I wrote when I first got the iPhone 12 Pro back in 2020:
The squared off sides look nice, but they’re less comfortable in the hand. [...] In comparison, the squared off edges on the iPhone 12 Pro feel harsh, and in my estimation, don’t even look as good. Next year’s iPhone 13 Pro is surely going to have a similar design, but I would love it if they did something to soften these edges a little bit.
My distaste for the feel of the iPhone 12/13/14 line of phones has been one of my more controversial opinions in recent years, but the rumors of softened edges on the upcoming iPhone 15 line of phones are super exciting to me.