An item's title changed but its cell still shows the old text after applying a new snapshot. Why, and what is the difference between reconfigureItems and reloadItems?

Predict first

What do a same-id snapshot, reconfigure and reload each trigger?

import UIKit

struct Item: Hashable, Sendable {
    let id: Int
    var title: String
    static func == (l: Item, r: Item) -> Bool { l.id == r.id }
    func hash(into h: inout Hasher) { h.combine(id) }
}
var events: [String] = []
final class Cell: UICollectionViewListCell {
    override func prepareForReuse() { super.prepareForReuse(); events.append("prepareForReuse") }
}
let layout = UICollectionViewCompositionalLayout.list(using: UICollectionLayoutListConfiguration(appearance: .plain))
let cv = UICollectionView(frame: CGRect(x: 0, y: 0, width: 320, height: 600), collectionViewLayout: layout)
let reg = UICollectionView.CellRegistration<Cell, Item> { cell, _, item in
    events.append("configure \(item.title)")
    var c = cell.defaultContentConfiguration()
    c.text = item.title
    cell.contentConfiguration = c
}
let ds = UICollectionViewDiffableDataSource<Int, Item>(collectionView: cv) { cv, ip, item in
    events.append("provider \(item.id)")
    return cv.dequeueConfiguredReusableCell(using: reg, for: ip, item: item)
}
let w = UIWindow(frame: cv.frame)
w.addSubview(cv)
w.makeKeyAndVisible()
var s = NSDiffableDataSourceSnapshot<Int, Item>()
s.appendSections([0])
s.appendItems([Item(id: 1, title: "a"), Item(id: 2, title: "b")])
ds.apply(s, animatingDifferences: false)
cv.layoutIfNeeded()
events = []
var s2 = NSDiffableDataSourceSnapshot<Int, Item>()
s2.appendSections([0])
s2.appendItems([Item(id: 1, title: "NEW"), Item(id: 2, title: "b")])
ds.apply(s2, animatingDifferences: false)
cv.layoutIfNeeded()
print("same id, new title:", events, ds.itemIdentifier(for: IndexPath(item: 0, section: 0))!.title)
events = []
var r = ds.snapshot()
r.reconfigureItems([Item(id: 2, title: "")])
ds.apply(r, animatingDifferences: false)
cv.layoutIfNeeded()
print("reconfigure:", events)
events = []
var l = ds.snapshot()
l.reloadItems([Item(id: 2, title: "")])
ds.apply(l, animatingDifferences: false)
cv.layoutIfNeeded()
print("reload:", events)

• same id, new title: [] NEW / reconfigure: [provider 2, configure b] / reload: [provider 2, prepareForReuse, configure b]
• same id, new title: [configure NEW] / reconfigure and reload identical
• same id, new title: [] a / …