It's not the high information density on the home page (common in Asia) but the overall web design style and functionality. The site was developed over a decade ago and has many interesting bits. For example, the "show me the product I ordered" page brings you to a captured JPG screenshot of the product listing.

And product listing pages look something like this:

https://24h.pchome.com.tw/prod/DSAM2L-A9007SS3R

Contrast/compare with these main players in China:

http://www.jd.com/

http://tmall.com/

http://taobao.com/