Change Vaadin loading indicator

When someting is loading, by default a vaadin loading image comes up. My question is, does this image come up by itself (without having to have been coded) or does one have to code it in?

The gif looks as such: http://vaadin.com/download/book-of-vaadin/vaadin-7/html/img/components/progressbar-indeterminate.png

How can I change it (I think it looks ugly)

Wow, I am so sorry. It doesn’t seem difficult at all. Just look through css files in VAADIN/themes and somewhere in that folder there will probably be a loading-indicator.scss or just do a Ctrl-F to search for loading. Quite self explanatory from there if one has any CSS knowledge…sorry for posting too quickly (forum abuse :D)