Multi-photo posts will now often start on the second image in a series. These “photo nudges,” as I call them, seem to occur when you scroll past an image without engaging with it. Instagram’s algorithm, growing smarter every day through the data users create, reinserts these series into your feed disguised as something new by “nudging” the second image forward. Whenever this happens, Instagram’s watching eye suddenly becomes a visible presence in my experience, and an annoying one at that.
Source: Why Instagram Made Multi-Photo Posts More Annoying – OneZero