First of all, the infinity sign is quite an aesthetically pleasing form in my opinion. But additionally, it symbolises the infinite passion and enthusiasm that all fans have for the sport - trying to hit home at the requirement of creating 'euphoria' and building 'anticipation before a big festival'. To a certain extent, this is also done by the heart-shaped centre circle in the football pitch graphic. Having said this, I would argue that the main symbolism of the heart in such a position is that of showing the love and emotion that football creates - and how Germany can be the perfect host country for this to unfold. This is inevitably also where the German flag and the Brandenburg Gate come in, as they are perfect icons of Germany in my opinion.
Additionally, this was all done in a fun way, juxtaposing the bold infinity sign and font with the more friendly, almost child-like, images inside the infinity sign. This, I hope, gives off a joint impression of Germany as up to the task of hosting such a prestigious event, whilst remaining friendly, approachable and open.