Your profile holds all your information and updating it is really simple.
Click your profile photo
Use the menu that appears to select Edit Profile
This opens your profile.
Complete any missing details
In this case, Jarvis is completing his Skype details so he can make use of one-click Skype calls from Blink. You can of course fill in any details you like.
Once you're happy, click Save Changes to return to the main Blink interface and you're done!