iOS 8 Safari has a bug that's preventing picture uploads to most sites. Some third party browses like Puffing and Chrome have been reported as working. If you have a third party browser, give it a try.
Chrome is free.
Puffin has a free trial version, good for 15 days. It's also handy to have around for those occasional sites that still use Flash or Java.
I have not heard one way or the other, but here are some other popular third party browses you can try.
Atomic
iCab Mobile
Mercury.