On the website:
To access photos you posted on social networks, click on the icons on the left hand side of the selection screen.
If it is the first time you login to Instagram, Facebook or any other network, you will be asked to enter your login information and accept the app permission.
Once you have logged in, you can browse your albums and type your friends’ name.
In order to select photos from your friends on Facebook or Instagram, simply click on the text edit field on the top left of the page and type the name or pseudonym of your friend.
Click on the red cross next to your friend's name if you want to go back to your photos.
On the App:
To access your Facebook or Instagram photos from your mobile, select your product and click on either of these networks in the selection part.
If this is the first time you log in, you will be asked to enter your login information and accept the app permission, just like on the web.