GCM and pictures

Hello,
i'd like to join a picture on my run results with stats. I have GCM for windows 10 (updated). When i want to put a picture instead of map, it doesn't work. I clic on "share", then photos with stats and so, i publish.... and nothing. My picture is not loaded and not registered with stats results.... I tried on my android smartphone and it works.... but not on my PC.
Any ideas/suggestions please?
Thank you.