Ecologist here!

This is a really interesting photo, you can very clearly see the xylem (water conduit) system in the banana. The phloem, which transports the "food" of the plant, is visible as darker bands around the xylem tissue which is lighter. I'm not a plant ecologist, though, so if I'm incorrect, let me know! In the actual banana fruit, the phloem is seen as the little stringy bits when you take off the peel!

I believe this is a healthy plant, as many of the bananas that die (at least in tropical plantations) are infected with Fusarium fungi, which will darken the xylem and other vascular tissue of the plant, causing wilt from accumulation.

Also, from first-hand experience, chopping down banana "trees" (actually a giant monocotyledon pseudostems, an herbaceous plant) is incredible satisfying. Also, also, bananas are technically a berry!

FUN BONUS FACT: I spent some time in Costa Rica, replanting native hardwood trees in a former banana plantation. I cut down a banana tree with my machete and found a Terciopelo (WARNING: NSFL PICTURE OF SNAKE BITE) or fer-de-lance underneath it! I nearly shit my pants and was forced to, unfortunately, kill the snake to avoid getting bitten. The nearest hospital is several hours away and Costa Rica's main highway has been under construction for about fifty years. Half of it is still dirt. A bunch of Ticos laughed at me. Pura vida.

BOTANICAL THEORY: Some recent papers have suggested that the brown spots on bananas actually fluoresce under UV light, suggesting that insects that may pollinate or use the fruit that can see into the ultraviolet may use the brown spots as cues to ripeness, as in their visible spectrum, the spots would stand out as incredible beacons of light.

DOUBLE BONUS SNAKE PHOTO: Here's a photo of a ten-foot boa constrictor I found on a hike in Costa Rica. I love snakes, but I high-tailed it the fuck out of there.