Earlier quoted context omitted.
Some people getting in the workforce in the last few years have troubles making the distinction between work and play contexts. It's extremely visible on github, slack, &c. which are more and more looking like discord / reddit (gifs, memes, random jokes in the middle of serious discussions)
In GH in particular, I’m not sure why images are allowed to be rendered in comments at all. They are almost always harmful. External links can be used instead
And it's consistent with the rest of GH's markdown parsing for README, issues, etc.