There are, all told, a total of 16,777,216 possible effects the Pop-a-matic Vrillyhoo Hammer can produce — this is the exact same number as the number of possible effects the Fluorite Octet can give, which is 8^8. This tells us that each of the 8 d8 in the Octet is considered unique and has its specific place in deciding which effect is activated.

That is to say, a roll of 1-2-3-4-5-6-7-8 is distinct from a roll of 8-7-6-5-4-3-2-1. How the uniqueness of each die is determined is presently not known. It could be that each die has its pips distributed differently so none of them are identical. It could be that the d8s are all identical but it is the order in which they land and give their values that decides what effect is activated.