Looks like King Asgore is in his natural state after a long day of gardening. Alphys seems to have sent him a device of some sort where he can capture memories and any scenes he wishes. So, he decided to take a picture of himself basking in his own lovely garden of flowers. Isn't human technology awesome?
Asgore (c) Undertale; Toby Fox
Art © Dralffeine
Image Copyright to Dralffeine; January 2018