The ways of getting such a printed image onto any website are:
(a) remove it from its frame, scan it with either a dedicated scanner or the scanning part of an all-in-one printer and then upload the resultant file to the relevant site ;
(b) remove it from its frame, take a photograph of it with a digital camera (or mobile phone) and then upload that image ; or
(c) leave it in its frame, take a photograph of it and upload the file.
Method (a) is best because it gets rid of problems with focussing the image and with unwanted reflections from it. Method (b) is better than Method (c) because you don't have to worry about reflections from the glass.