So this explores the possibility that some over dimensional "benefactors" could find our struggles to survive interesting enough to "collect" our minds for scientific purposes when we die.
And after those studies they kindly give us whatever paradise we wanted during our life. Forever...
It's implied that those mysterious entities do all that without asking our consent, and later without informing us of the fact that our afterlife is essentially a simulation.
And if we choose to self-terminate they simply reboot the simulation, again and again.
A bit like in "The Suit", a technologically enabled being engages in actions that affect us, and that happens beyond our control. But here there's no cautionary tale. It's not our tech.
However, just like the suit, those beings don't seem to care much if we suffer in the process. Their ends justify their means.
The "Masters" on After Life treat us like we do with guinea pigs in our labs.
We don't do our experiments to make them suffer, even being aware they endure some suffering. We even try to minimize it.
Perhaps that's one moral question the author considers relevant: "Put yourself in the place of a lab rat. How do you feel?"
I tend to agree, with the difference that, to our knowledge, lab rats are not sentient (in the sense of "I think, therefore I exist").
That leads to another frequent questions in Science Fiction: Are we sentient, in the view of some extremely advanced being? Or are we placed in the "smart animal" category? Some of the best SF stories are those able to push us outside our anthropocentric point of view. Which in turn opens space for some self-reflection
Another question: Why can't these all powerful entities make our simulated afterlives more interesting?
In the story it's because they use our own brain as sole source of information for our simulation.
But why would they have such limitation?
They have access to an unlimited number of brains (or souls, if you want to call it that way), and even if they don't the simulation software should be able to create new situations and new "Non-Playable Characters" easily. Damn, we can already do that on our games.
Also, why they reboot our afterlives? If we chose to terminate, why restart?
Their computational resources are unlimited? Even if they are, what would be their motivation?
Is the author trying to ask: "What would you think if you know for sure there's an actual afterlife, but it's not provided by a benevolent God, but rather a simulation ran by ultra advanced beings from another dimension?"
Or yet "If we call these being(s) God(s), if they collect our "souls" when we die and, after a brief(?) analysis, offer us the after life we always wanted, is there really a difference?"
BTW, again Iain M Banks' Culture fans will find similarities with topics that exist in the books, like the "snapshot", that's akin to a copy of someone's "mind state" in the Culture, the existence of "simulated afterlives", that is particularly relevant on "Surface Detail", and the existence of super dimensional beings.
And the reference to "Seven Higher Dimensions", that together with our usual four makes eleven dimensions, matches exactly the number of dimensions mentioned by Banks...
All that said, it's an interesting story, much less frightening than "The Suit" (unless you consider frightening dying of boredom after living thousands of years in paradise) and the art is beautiful, as usual.