1. One of the fish is 'making eyes' at the other. Both are male. As you know, homosexuality is frowned upon in the fish kingdom and thus such a display is unlikely to happen on a bus.
2. The girl with the backwards hand is touching the ‘chime strip.’ That particular ‘chime strip’ is broken. She was probably told this before taking her seat.
3. The bag reading "chips" is clearly filled with Pringles, which are not marketed as 'chips,' rather they are 'crisps.' Also they are sold in cans not bags.
4. The tag on the boy's bow tie says "Made in China" but it was, in fact, made in 'Japan.'
5. The girl is wearing an "arrow through the head" to be like Martin Short. However, this gag was actually not Martin Short's but Steve Martin's.
6. Girls aren't funny.
I can't find #7. Can you?