It’s Nap Tide
It doesn’t seem too horrible, does it? The chilly sea, a bathing suit, and the sun in the sky. Well, reconsider. Grandma mistakenly believed that she was just dozing off on the beach, but she overlooked the tide.
She will therefore find herself floating and dozing together when she wakes up. We simply don’t understand why her relatives felt that getting her picture instead of waking her up was a better idea.