Does anyone know what this joke means?

1, grandma recently caught up with the fashion and insisted that her grandson teach her to chat with QQ. On this day, grandma pointed to the head of her grandson's QQ friend and asked, "What do these colorful things mean?"

Sun Tzu explained, "These are all online friends."

Grandma asked again, "What about the one who jumped?"

Sun Tzu smiled and replied, "That's someone talking to me."

Grandma pointed to the heads of several friends who were not online and asked, "Are all these prostitutes gone?"

Grandson listened and asked in surprise, "How do you know?"

Unexpectedly, grandma showed a dismissive expression and said, "Black and white photos are hanging out, and they must be gone."

The rising sun smiles on the east mountain, and a plane flies towards the sun.

When the old lady saw it, she stamped her feet in horror and pointed at the plane and shouted, "Fly higher, fly higher!" " "

The plane flew by, but the sun was still there.

The old lady sighed, "Young people nowadays are so reckless. If I hadn't reminded him, he would have hit the sun!" " "