If a user opens a photo of Adolf Hitler or other Nazi-related imagery in MediaViewer, such as the one below, then right next to the copyright information there is a symbol of a swastika with an exclamation point inside of it. Mousing over the symbol informs the user that:
This image contains Nazi or other fascist insignia which may be banned in some countries.
This was a feature implemented by T102693.
A bug/problem with this feature, however, is photos of a Jainist or other religious swastikas (example given below) are also tagged as containing Nazi/fascist imagery.
This is a problem as many religious swastikas are in no way related to Nazi Germany and are almost always completely legal when used in a religious or non Nazi-related context. This appears to be due to their inclusion in "Category:Nazi symbols status".