No one seems to know, what are the smiley face, mouse and tear drop in a circle for?

You collect one smiley face each time you click on a mouse/trash/teardrop in your own mansion and 4 (or maybe 5?) when you find them by visiting other ppl’s mansions. The owner of the mansion also earns one smiley face in this case, and you can collect those you earn that way by visiting the wish tree. If you have any to collect, it will have a smiley face above. Once you have enough, you can exchange them to upgrade de wish tree/sand castle.

The tear drop in a circle is to water plants. Tap on it & it'll move to whichever plant needs watering. Tap on it again to water. When you tap the mouse, the mouse goes into a live trap (for relocation). When you do these things while visiting a friend, you get a life & you give your friend a life. The more friends you visit & tap on whatever task pops up, the more lives you give & receive. That's why visiting friends is a good thing. No clue what the smiley face points are for!

Apparently it's for updating landmarks like the wish tree