The Card links to a thumbnail

serializers.py

class CardSerializer(serializers.ModelSerializer):
    title = serializers.CharField()
    song = SongSerializer(read_only=True)

    thumbnail = HyperlinkedSorlImageField(
        '300x300',
        options={"crop": "center"},
        source='image',
        read_only=True
    )

    class Meta:
        model = Card
        fields = ['id', 'title', 'link', 'image', 'song',
                  'thumbnail', 'desc', 'is_paid', 'price']