2. answer 1.
You cannot claim a scene's intent by guessing out of nowhere. DoTA applies here.
So you deny it's a reasonable assumption that Sans stepped on the stick?
It's a "tough" branch, he'd have to do that intentionally. Accidentally would conclude that his weight alone did that.
& what if his weight did that?
They don't have to. The audience's knowledge is a nonfactor. Sans did that through unknown means, that's the immutable fact. saying it's through a stomp is an assumption, and the lack of ANY other demonstration of this kind of feat makes this very iffy.
If I recall the scene correctly, we see a shadow following, it walks, there's a snap, then it disappears.
This is very typical storytelling. We don't have to know Toby Fox personally to make this conclusion.
Whatever his intent, this could be many other authors & the simplest conclusion would be the same: The thing following the human stepped on the stick, made a sound & went back into hiding.
Looking at in isolation, logic says Sans the lazy skeleton, would not, while trying to stealthily follow (For a joke or not.), use his magic to break a stick when he's trying to hide.
& saying it's a fake-out requires assuming he'd put in that extra effort of doing the fake-out & hiding. Not to mention, saying it's a fake-out or saying he used magic also requires assuming what he did.
Of course, I'm not saying that's your position, you're saying he did it through Unknown Means.
But when we don't know what happened, we can usually assume, & whether viewed through the lens of the story's events in isolation, or through the lens of "What do authors use these kinds of scenes for", it's easy come to the same conclusion.
Regardless of how we feel about the results of the Calculation itself, the BASIS for doing the calc seems reasonable, EVEN as an assumption: The stick was stepped on.
That's because you think the audience needs to figure that out. They don't.
Usually, something in a story happens with a purpose. Perhaps character development, setting the mood, worldbuilding establishing lore, or a pivotal moment.
Things happen in a story because there's an audience to be engaged by that story, & things that serve no point in the story are often avoided or removed, much less made mandatory.
In this case, the point of the scene seems to be a small jumpscare & establishing Sans's character.
If the audience doesn't need to figure out what happened in this scene, then why does it happen?
If the audience doesn't need to figure out what happened in this scene, then why there is a new sprite & dialogue for the stick being broken?
Be it Toby Fox or whichever author, things in fiction, especially "mandatory" experiences usually have a point to them.
I'd say that even if we didn't care who the author was, it's still reasonable to assume there's supposed to be something for the audience to become informed of through this scene, & that the stick was stepped on happens to be a reasonable conclusion for such.
That also applies to any physical feat from Sans?
The point of what I said is that we don't know if he can use his Telekinesis on anything but SOULS.
We only ever see him do so on the SOUL. Why assume it's the author's intent he can do so on other things, like wood?
But you don't need magic to crush wood with bones.
This also works in my favor, though. I explained and showrd that he DID portray this as a somewhat relevant feat, "this is a tough branch!" (Said by the narrator), "It was smashed like nothing..."
So this absolutely is being intended as someone dangerous, therefore we need further proof that a weak monster like Sans is capable of doing so.
I'd argue that's questionable; "Tough" for the standards of Frisk, who explicitly can't lift said branch.
& if the scene is implying they're a threat to Frisk, whether they might be superior or inferior or whatever, then why deny that? Other than being called the weakest monster (Which is a vague comparison.), what anti-feats does Sans have?
As for weak monster feats, I don't recall the weak monster feats very well.