If you want to change the photo of a game user, you can perform the following steps:
Press this button on the app bar of the game view to show the list of secondary commands. On a PC, you can use the menu of the title bar alternatively. This menu is more detailed than that of the app bar, so you can reach almost all the panes directly.
If a camera is connected, you can click this button to take a snapshot. The camera app allows you to do this. The picture taken is shown in the photo panel.
Click this button if you want to load a picture from a file. A File Open Picker allows you to go to the target folder step-by-step and select a picture file from there. Only files with the name extensions ".png", ".jpe", ".jpeg", ".jpg", and ".gif" are shown. The photo loaded is shown in the photo panel.
Click this button to cut and paste the selected area to the user photo and to return to the previous pane.