I exported all my photos and video's to my windows 8, updated my software on my iphone 4s to io6 and a usb symbol with an arrow pointing to the itunes icon appeared on my phone and I can't get it off. Please help.

I exported all my pictures and videos to my windows 8 computer. Next I updated my iphone 4s software to io6. When that completed the image of the usb plug with an arrow pointing to the itunes symbol appeared on my phone. I can't get it off and nothing else works. I tried rebooting, holding down the off button and round button at the same time. The image still appears. Can anyone help.

Thanks