What's that word that means "typical of / a small version of / illustrative of"?

Solution 1:

The word you want is probably indicative. The smaller example is an indicator of the conflict going on in the larger context.

Solution 2:

bib's answer is good, but if you are looking specifically for an adjective, emblematic is a good fit.

Solution 3:

Instead of ... is [something] of ... You could say epitomizes

to serve as the typical or ideal example of

Solution 4:

I believe microcosm does encompass all of the meanings you were looking for. I know you ruled it out above, but it does fit.

The Google definition: a community, place, or situation regarded as encapsulating in miniature the characteristic qualities or features of something much larger.

You could easily say the battle between them is a microcosm of the greater shift.

Solution 5:

Such relationships are very often described from the opposite perspective as "A is B writ large"

If one thing is another thing writ large, it is similar to it but larger or more obvious:
Hollywood is often said to be American society writ large.

Although the corresponding writ small is about 15 times less common, that's just a relative thing. There are over 20,000 written instances of it in Google Books - for example,...

"The self is simply society writ small."