The picture in of itself is very tiny. When small images are blown up they tend to get pixelated and blurry.
Normally when I edit Banners for Youtube I'll take a Banner Template of the current year and put all the pictures, graphics and text inside the boxes. That way I'll know if my pictures or text are too small or not since the template gives you the dimensions of the banner. But I normally do this through Photoshop but I'm sure you can pull the same template into TinyPic. I hope that helps. I'd need more information before I can go more into details.