This is a circuit board layout for a weather sensor. A BME280 is used to measure temperature, humidity and air pressure. In addition, an NTC ( B+B Sensors TS-NTC-103) is used for temperature measurement, the accuracy of which is significantly better than that of the BME280. The recorded data is sent to a receiver by radio (nrf24 module).
Power is supplied via a CR2032 3V coin cell. The name comes from the fact that the circuit board fits into a kinder surprise (egg).
The creator of this PCB is @Spaghetticode from arduinoforum.de. I have only implemented his design in KiCad.
https://www.arduinoforum.de/arduino-Thread-SensEgg-light-FunkSensor-ATtiny814-nRF24-BME280-NTC