Yes, the frequency alone does trigger the Apple Pay screen. Though this is a vast oversimplification of what's going on, and I'm struggling to use the right technical RF terms to explain the interaction.

I personally hadn't seen this till this morning by putting my iPhone and WiiU gamepad together. It seems Apple did this to try and increase the speed of payments, possibly as a way to help spur adoption by keeping friction down wherever possible.

Google Wallet on some Android phones will wait for the connection to progress a little further between the phone and the other device/tag, activating only if it gets back the "this is a payment terminal" identifier. This likely is due to the wider use of NFC on Android where the communication needs to occur for the phone to know what application to notify.

Looking up more on this behavior, I did find someone else joking about their elevator accepting Apple Pay. Also seems Sony released an Android phone that also skips that initial check and launches into a photo app when it senses any NFC readers.

Couldn't find a way to disable this though, even after toggling "lock screen access" for Wallet. I'm surprised iOS 9.2 left no way to change this behavior as it is impacting some people's use of boarding passes or other non NFC based wallet items. This is happening when a combination optical scanner for QR codes and NFC reader is used.