These are "Big Frame Magnets" that were sold online as part of an online lottery event called "Manpuku Gacha". They're mostly remarkable due to their size (approximately 11 cm x 7 cm) and concept, basically acting as miniature paintings. The actual art is about 8.5 cm x 5.2 cm. Five variants were produced. Their appeal is limited other than as a novelty, but they're not a bad way to decorate a fridge.