No, a mini adapter is supplied free of charge with the device. Just clip it onto the European size plug and you're done! The socket will not be any bigger and the item will work as if the socket had always been Swiss :)

(This is the adaptater : https://www.galaxus.ch/fr/s4/product/max-hauri-adaptateur-de-prise-de-courant-type-ef-cee-77-adaptateurs-pour-prise-electrique-6154968)