Anyone guess what this is about? What's the message?

Yes, according to the ICRC website the first chinese office of the Red Cross was opened in Beijing in july 2005 (almost like Cpod in SH).

http://www.icrc.org/WEB/CHI/sitechi0.nsf/htmlall/china?OpenDocument

...same page in english :

http://www.icrc.org/Web/eng/siteeng0.nsf/htmlall/china

Your query spurred me to go onto their website to dig into who they are. It appears that the local Blood Bank is some kind of joint venture between the Red Cross and the local and provincial Health Bureaus, much like it is in the West. So, in fact it is in a way a 'Red Cross' bus, or at least valid to refer to it in this way.

@Kimiik

It's not actually a Red Cross bus - that is why I put the Red Cross in inverted commas. In Australia the Red Cross is the organisation that collects blood donations - I'm not sure about other countries. Sorry if that caused confusion.

Could the name "Red Cross" (红十字) be used for a bus of the chinese health administration ? For me, Red Cross is the name of an international humanitarian movement.

You are spot on Barbs; it is indeed a 'Red Cross' bus parked at a busy shopping centre.

I'm a bit puzzled about people not being able to see the photos - I am located well inside the PRC and I can see them (yes, they are on Flickr.) Can any technical poddie offer a comment?

I also can't see posted photos lately. Or pictures in wikipedea. I have tried different browsers to no avail. I have not problem with videos on BBC website, so I don't think it is my internet speed... I am very sad. 我很伤心