This is what it looked like:
Yeah, that's right. It's a penis tree. Uncovered during restorations, it was hailed as a glimpse into the medieval world of political insult (note the German eagles — then representing the Holy Roman Empire and its Ghibelline faction) in flight, while a group of women look on. The women have also been interpreted as witches performing a ritual in which severed male members were placed in birds' nests. Yeah, mediaeval artists were weird.
When first discovered, the fresco lay underneath a layer of whitewash, and the penises had been plastered over with inoffensive flowers. But that was not to be the last indignity the work was to suffer.
This summer, after years of restoration, the fertility tree was re-opened to the public. Art historians were not impressed. The restoration team were accused of fading out the phalluses, and in some cases, gelding them:
The Daily Mail reports:
Chief restorer Giuseppe Gavazzi denied there had been any intention to remove the penises that have disappeared and said: 'It's possible that the aggressive nature of the chemicals used made them disappear.It's difficult to find "after" photos online, but La Nazione had this screencap:
'It was not a deliberate act. People have to remember that the fresco was already in a very poor condition when we started work on it and the restoration was carried out accordingly.