That weirdo crossed over connector doesn't make sense for ethernet. Any relatively modern PHY won't care about polarity within the pairs, and the 4/5 and 7/8 pairs aren't used in 10/100, so why bother crossing them at all? Unless it's gigE, which certainly wouldn't care about pair polarity. Maybe some sort of non-standard PoE, and it was easier to manufacturer the connector symmetrically and swap both outside pairs?
There are plenty of other uses for 8P8C connectors, like RS485, RS232, etc, so I would guess it's for something like that. Maybe a console connection where someone forgot to swap the DTE/DCE ends between two designs?