diff --git a/packages/contracts/src/interaction-guarantees.ts b/packages/contracts/src/interaction-guarantees.ts
index 825898cd8..2e0311fe5 100644
--- a/packages/contracts/src/interaction-guarantees.ts
+++ b/packages/contracts/src/interaction-guarantees.ts
@@ -170,6 +170,15 @@ const RUNTIME_TREE_SHARED_GUARANTEES = {
   // not the bulk one. Every other platform, and any backend that omits the
   // hook, refuses on the visibility resolver's verdict unchanged — this is a
   // rescue-only override, never a way to relax a genuine refusal.
+  // The live read is a SEPARATE runner request (the direct querySelector), so
+  // it shares the runner's prepareActiveCommandContext surface policy only with
+  // a RUNNER-ROUTED capture: eligible simulator captures go to the host AX
+  // bridge (packages/platform-apple/src/snapshot-route.ts), and a bridge-served
+  // capture never reaches that seam. #2448 puts the system-surface case (the
+  // web sign-in sheet) back on the runner, where both reads do share it. Either
+  // way this is not a same-instant guarantee — no captured surface identity
+  // crosses the two requests, so a surface that appears or dismisses between
+  // them is undetected.
   offscreen: {
     kind: 'runtime',
     via: 'src/commands/interaction/runtime/resolution.ts#throwIfOffscreenInteractionTarget',