How to take screenshot and raise an issue for website from mobile device?

May be you can use the browser firefox and change the compatibility mode to mobile device and then take a screenshot from it as being the responsive site. Or else you can also use the problem steps recorder in windows to record the issue.

Issues will be different, while checking in real device and when we testing by resizing the browser. So it would be great if we have a facility to update issues of a website from mobile