Some potential reasons:

1. This was taken with Windows’s snipping tool. If you click on the image, it draws. AFAIK the default color is red.

2. This was screenshotted on android, and cropped later. They accidentally drew on it when trying to manipulate the image.

There are other good reasons, but if it was engagement bait, oh well…

It’s to get past the softwar* censors

Looks like it worked!

HOW THEFUCJK DİD YOUBSEE İT

It’s a cue mark to let your browser know it’s time to load a new gif.

There are only 4.29 billion possible values of an int32, so even if you used 2 lines for each case, it’d still be under 10 billion lines of code

bool isOdd(int num) {
    if (num == 1)
        { return true; }
    if (num == 2)
        { return false; }
    if (num == 3)
        { return true; }
    …
}

One word: debiggenify