Questions regarding ASUS N43 Speaker

Greetings fellow computer enthusiast  

I recently purchased an ASUS laptop, model N43SM-VX102D and I found some odd things that puzzles me quite a bit and would like to ask about several related things such as:

1. Odd speaker component?

Under several ambient lighting conditions I found out that my laptop speaker's internal component is asymmetrical. this is the image http://sadpanda.us/images/1145306-A8DLP8U.jpg from the left side of the speaker grille. Strangely the right side of the speaker does not contain the same round component. Is this normal? Can you tell me the name of the component?

2. Does metal case gives in in laptops? or does it indicates build quality/craftsmanship?

Pardon my bad English. Looking forward to the answers