169.254.x.x address manually assigned to a printer yet can still communicate through WSD

I took over a small office (3 offices, 2 printers, wireless clients) tech position a few days a month. The previous technician setup a networked color printer and manually input a 169.254 address. The printer is working through a wired PC and a wireless Macbook through WSD/Bonjour. Lastly, the rest of the network is using typical private address space of 192.168.x.x.

I'm not too familiar with WSD/Bonjour so I don't know how exactly they can communicate. Can anyone elaborate? What's more is why would someone manually use a 169.254 address as this is often self-assigned when DHCP fails? Lastly if there was no WSD/Bonjour would your typical router learn to route between 169.254.x.x and 192.168.x.x?

Thanks for any insight