To how your Instagram Posts and Feed on your account, the first step is to link your Instagram account in your Account Settings.
Click the Link Account Button and you should be redirected to log into your Instagram Account.
Once logged in, your Instagram account should be linked and you can now use the Instagram app to show an Instagram Image Wall, or individual posts.
To use the Instagram App on your slides, simply click the Instagram App Icon in the Mango Slide Editor, and choose a layout.
Portrait - Display a single post at a time in a portrait mode on your signs. This is useful for screens that are set up in a portrait orientation instead of a landscape orientation.
Landscape - Display a single post at a time in landscape mode on your sign. This is useful for screens in a landscape orientation.
Image Wall - Show an animated Image Wall of pictures from your Instagram account. This is useful as a background. Even combine with Portrait or Landscape of the the top of the Image Wall for a neat effect.
*** Troubleshooting Tips ***
How to Link a different Instagram account: If you have already linked your Instagram account, in order to link a different Instagram account you will need to click the Unlink button in the Settings page. Once the account is unlinked, then you will want to go to your Instagram account on the same computer https://www.instagram.com/ and Log Out.
Once you Log out of your Instagram account, you can try and Re-Link your Instagram account through the Settings page, which will prompt you to log into the new account.