There is an image circulating on Twitter. It is a photo of Facebook A/B testing on its loading icon on the splash screen. In A group the loading icon resembles Facebook's loading icon (on the left) and in B group the loading icon resembles iOS' loading icon (on the right).

Facebook A/B Testing Its iOS App's Loading Icon

There is an interesting find out of the test: If the loading is slow and the icon is the Facebook's own one (left) the user thinks that the slowness is because of Facebook's itself. On the other hand, if the user feels slowness and the icon is the iOS' one (right) user thinks that the slowness is due to her device. This leads us to the conclusion that "every single detail different from the masses attributes to your corporate identity".

Actually it is not new. In social psychology this is known as attribution bias:

"People constantly make attributions regarding the cause of their own and others’ behaviors; however, attributions do not always accurately mirror reality." [from Wikipedia]

Hence try to make the best design decisions in order not to hurt your brand.