OP, i feel it attempts to convey much more than just a striking similarity.
i believe it is meant to be understood quite literally, in the sense that what is manifest at "higher" degrees of consciousness, or dimensions, is equally manifest in its consequent "lower" degrees of consciousness.
the concept we speak of is most easily witnessed in nature's repeating patterns.
as above, so below..or as below, so above..
or what is seen, is merely a reflection of the unseen which causes it.
a tree for example, is very similar in the appearance of its flowering branches in relation to that which is not seen, its roots.
even in examining the leaf of the tree, we see the macro within the micro..
the entire tree's pattern and design is emulated through the veins and stem..
the very shape of the leaf emulates the overall shape of the tree itself in many cases..
Unity or the Whole is represented and manifest through its parts, as Unity or the Whole is reflected
in each of those parts..
and to think..it all starts with that One little seed that contains the tree in its entirety..
although quite similar, no two trees, or branches, or leaves are identical..
it is possible that an entire forest originate from One seed..
one seed-->many roots
one tree-->many branches
one forest-->many trees
All from One.
mostly, we only choose to see pieces of the patterns and note the differences..
when we look at the "big picture", we tend to see your perspective of "striking similarities"..
for others, such as myself, there is only Unity.
i assume this perspective only depends on how far we are willing to "zoom out"..
as far as the context of humanity and RGT and the nature of our existence..
well, it seems to me that we too emerge into this grand world in diversity, all originating from a single Source.