When you are setting up a new brand on social media platforms two things are important. For one, you will want to try and secure the same handle across social media platforms. Most importantly though is securing the same handle for Twitter and Instagram for ease of cross-posting.
Your profile picture will display as 110 x 110 pixels in the mobile app. However, the profile picture will appear slightly larger on web so it is suggested you upload an image that is 180 x 180 pixels to maintain a high-quality image in both settings.
Your Page’s profile picture:
Displays at 170×170 pixels on your Page on computers, 128×128 pixels on smartphones and 36×36 pixels on most feature phones
Profile photo (recommended dimensions are 400×400 pixels)