You can now display your Instagram photos using the new tall 4:3 ratio that Instagram has introduced to the grid layout on your profile.
To update your existing widget (or create a new one), head over to the widget settings page for your widget and set the Photo Dimensions option to the new 3:4 (Tall) option and save.
Please note, you will need to update the code snippet on your website to support the change.
Create your new 3:4 grid ratio Instagram widget here.
