I assume you're using webcam footage for the thumbnail. The photo it'self isn't the worst in the world, but I would recommend adjusting your light placement. I'd learn about lighting. You don't have to spend much on lighting, you can get yourself a cheap desk light, or even a cheap usb ring light to put on the side so it doesn't give such uneven lighting. It actually looks like you're being lit by your monitor or laptop.
As for the characters, you can get rid of the "cool one" and then the one with the knife in it's head can be blown up MUCH larger. I'd go with a differant font for "wow" make it simpler text, and then with a bigger character in the left, the "wow" will have more impact.