With two clustered nodes fronted by load balanced with session affinity turned on (by IP), if you set a global logo as administrator the logo file does not get replicated onto both servers (was broken link on one server and viewable image on the other). This issue was seen on several different computers/browsers, so it is not a cache/loading issue in the browser.

The workaround was that we specified the server address specifically in the browser of the server not containing the logo and reset the global logo to the same logo. After this, both servers showed the global logo.

It would appear that all files are not getting replicated between the clustered servers which is a great concern.