Overall, it sounds like Instagram is testing out this feature before it becomes permanent. To see if you have the ability to open multiple accounts with your Instagram app, head over to your profile and click on settings. If you have the option to add an account, congratulations. Those with multiple Instagram accounts are discovering that when they receive a notification, it does mention which particular account it is related to.
Many social-media apps already offer the ability for users to open more than one account, and quickly switch between them. Unfortunately, Instagram is not among them, at least not for everyone right at this moment. Based on these tests however, it won't be long before Instagram users will be able to post pictures of their meals on multiple accounts with a quick click of a toggle switch.
Screenshots show multiple account support for the iOS Instagram app
source: Engadget via Latergramme