When we make a bamboo fly rod, we have to deal with the nodes. These are like knots in a piece of wood. The grain of the bamboo often changes direction a bit here & so the nodes must be straightened out & flattened by the rod maker. It's also because of this irregularity in the bamboo grain at the nodes that we don't want two nodes next to each other on adjoining strips in the finished rod. As a result, the rod maker must stagger the nodes in the layout of the bamboo strips, so no two nodes are next to each other.
The term mirror matched tips basically means that where you see a node in one tip section, you will see a node in the other tip section in exactly the same place:
Of course there are many rods made with two tip sections where the tips are not mirrored in their node placement. Most of the time this is no big deal & it doesn't mean that the rod is inferior in any way. Often times the raw bamboo a rod maker has to work with will not allow for mirrored tips. In fact, some of the sweetest feeling bamboo rods I've ever cast did not have mirrored tip sections. As bamboo is a natural, growing plant, Mother Nature often has as much to say about exactly where the nodes go as does the rod maker.
Now the next time you hear a rod collector, vintage rod dealer, or any bamboo fly rod aficionado mention a rod with mirrored tip sections, you'll know exactly what they're talking about.