As far as I can tell, it looks the same to me as 2.0 and if you wanted to change its appearance, you can go into the index.html file and change the css for #appLoadingIndicator.
Isn't it, that in sencha touch 2.0 the background was white and 3 dots was showing up asynchronously and now in 2.1 wersion the background is blue and dots are showing up synchronously (3 can be seen at the same time)?