I'm guessing someone will take a $10 esp32 chip and put this code on it and just drop the esp32 in some hidden location and it just sending images to any open airdrop that passes by.
ESP32 theoretically can provide all of the hardware requirements (WLAN monitor mode, BLE) but there is one missing part:
> Triggering macOS/iOS receivers via Bluetooth Low Energy. Apple devices start their AWDL interface and AirDrop server only after receiving a custom advertisement via Bluetooth LE (see USENIX paper for details). This means, that Apple AirDrop receivers may not be discovered even if they are discoverable by everyone.
If someone reverse engineer BLE advertisement, yes they can build such hardware.