DMCA: Oh bullshit. Look at the factors considered in fair use for a second will you, this clearly falls under it.

1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;

It is highly transformative (a video -> a still at low resolution with commentary applied on top with meaning presumably unrelated to the video), it is not being done for profit.

2) the nature of the copyrighted work;

It's not fictional, it's been published.

3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole;

It's a single frame, scaled down, out of a video containing many frames (usually 30 per second of video), it is presumably not a frame particularly relevant to the content of the video (since it sounds like it primarily contains OPs face). This is a very small portion.

4) the effect of the use upon the potential market for or value of the copyrighted work.

As far as I know the youtube video had no potential market value, even if it did, taking a frame from it and publishing it elsewhere isn't going to decrease it.

You have a legal duty to consider fair use before filing a DMCA request.