This is the 532nd most frequent Portuguese word.
"Instagram" in Portuguese refers to the social media platform used for sharing photos, videos, and messages.
Here, 'Instagram' is used as the platform where the action of sharing a photo took place.
Eu compartilhei uma foto no Instagram.
I shared a photo on Instagram.
In this case, 'Instagram' is the context within which the activity of following artists happens.
Você segue muitos artistas no Instagram?
Do you follow many artists on Instagram?
Here, 'Instagram' refers to the platform itself as the subject of the sentence.