It’s common to use platforms like Instagram as a popularity scheme, but it could also be used as a social weapon. Popular Instagrammers have consistent “looks” to brand their feeds. This might involve the use of a single filter or similar color palettes that maintain sleekness in one’s outward appearance online.
If someone decided to suddenly shift that “look”, perhaps in a radically different direction, this could indicate something is off, or something new is happening. Breaking conventions can be used to spark interest in a new post. If one normally uses short captions, an unexpectedly long caption might pique a viewer’s curiosity.
First posts can also do this, moving the look from nothing to something. Instagram profiles with one post force visitors to only interact with that post.
Following other profiles sends them notifications and can entice someone to open your profile. If you wanted to spread information in a low-key way, you could create that point of visual intrigue and follow everyone who you would want to see that post.
Think of Instagram as a form of tactical media and social tool. Attract people to one post, and the information will be understood as far more important.