What does it means when someone request your photo to be featured in wiki. Who could that person be? Does that mean the photo quality is good enough or they randomly choose?

My guess would be someone is trying to create a Wikipedia page(contributor) and is looking for a picture to be included in his article. He did a quick google search and bumped into your photo.

Wikipedia images are screened through. Not every regular photo will be approved. However Wikipedia itself very rarely create content on their own.

hmm..that sounds ok. because this guy has once requested for my photo and it is already in wiki. now he comes for different photo. he goes by a chinese name. but not sure malaysian or what. is there of any importance contributing to wiki? maybe u can payment or some sort?

just make sure you make clear with him about the copyright of your photos.

public domain? all right reserved? or any other creative commons licenses (http://creativecommons.org/licenses/).

maybe you have already defined it in your flickr so he just use your photos according to the cc license?

Ya. No issue on copyright because he asked me to release the photo at first. But is there any possibility of money making activity here?

What is the page about?
If you believe that the wiki page is created/used for promotional reasons, you may request for payment.

Otherwise, that person is probably updating the page out of his own interest (for free probably) and he most likely will not be interested to pay for a photo.