If you have a mouse with a wheel, then pressing CTL + moving the mouse wheel up (for larger) or down (for smaller) also works.
The top right, I've got the same thing as well, only larger! However, on my system, it's due to my graphic settings. All it is is the banner repeating itself. I have to zoom in to 125% on my browser (Chrome - 100% zoom is normal) to make the original banner fit. The
header is 1600 x 212. My display is 1920 x 1080. Because of this, the header has to make up for 320 pixels (1920 - 1600), so it repeats itself. I prefer my browser to be at 100% zoom, rather than having the banner fit my screen, so I ignore it!