So, getting this out of the way, this chapter's contents were also adapted into the anime, as the final segment in Episode 4, so it got shifted in sequence to between the Christmas events and the New Year's events, which... didn't seem like it was a terrible choice- basically it makes it so he's already princess carried Mahiru to his bed once before when she falls asleep on New Year's, and it helps to reinforce why she might be exhausted then (recovering from being sick), besides working all day cooking during New Year's Eve.
Every so often, the anime was doing alright compared to the manga, but beyond Ch.17, I'm pretty sure it'll start to slide drastically. We already saw a scene completely omitted from the anime that was included into the manga adaptation last chapter with Mahiru and Chitose having a girls' day/night out, and Amane goes out to meet her and escort her home. All other scenes before this chapter were at least alluded to or ended up elsewhere in the anime, I think, but that one was just gone, far as I recall.
Long and short... anime adaptation is going to be falling off past this Chapter compared to this manga adaptation, and likely only cover a few moments or conversations going forward, while the manga should be fairly faithful to the LN. The biggest difference I've gathered from comments by others between the manga and the LN is that Mahiru is normally colder in the LN, while in the manga she's pretty much always a cutie.
Anyway, this was a cute scene, even in the anime. Seemed like it got adapted alright, but the manga still executed it better.