Hi Annarita, great article!!
In “Starting from version 28, Firefox will support picture by default too”, I think you meant to say “version 38”, right?
Following your examples, I managed to implement picture correctly.
But I couldn’t make the img with srcset work…
Do you know what I did wrong?
http://codepen.io/saviomd/pen/GgYgLd
(picture is working in chrome 41, img with srcset don’t)