img.get() sometimes returns an image and sometimes an array in p5.js

Question

Im trying to do sprite animation in p5.

let spritesheet;

function setup() {
    createCanvas(innerWidth, innerHeight);
    spritesheet = loadImage('./spritesheet.png')
    background(0)
}

function draw() {
    let img = spritesheet.get(0, 0, 100, 100)
    console.log(img)
    image(img,0,0,100,100)
}

When the y is 0

let img = spritesheet.get(0, 0, 100, 100)

It works fine but when I try to adjust values of z or y it breaks

let img = spritesheet.get(0, 100, 100, 100)

Here is the console log