The human brain is a starting place for comparison.
Even if Sapiens plurum does not resemble homo sapiens, having a basis for comparison at least gives us a Bayesian starting point.
Sapiens plurum meta intelligences are communal entities that operate on at least a planet-wide scale. As relatively tiny actors operating on a minute scale, we do not know which state of morphogenesis this being or beings developing outside us may be in, any more than we know what occurs within us at the quantum scale. Is it some infinitesimal universe operating far beyond light speed? We can only speculate at things so far outside our timespan and perceptual range.
What we can delineate is the line between our own actions and the actions of the meta-intelligence. This affect one another, but are distinct. We make decisions and behave in ways that result in action at the human level. Billions of humans acting in billions of ways can result in billions of movements. This is because each entity can decide and move itself and its tools. An AGI can help humans at this level make better decisions because its shared computational power can enhance humans' severely constrained attention channels so that they can make multiple parallel decisions and consequent actions more effectively.
However, at a meta-level, if our communal being acts as a single individual to, say, crawl around the galaxy, it will have the same attentional constraints as individual humans do now. It will need to turn many sources of attention into a very few actions, as handled by Bottlenose Labs apps.
Attention is just one example of how intelligence at the Homo sapiens and Sapiens plurum levels will vary. I hope that the Global Brain Mapping Project provides a means to investigate and communicate these phenomena as they develop so that we can impact them in positive ways.