Krack attack(er) sees which traffic?

If either endpoint is patched you should view the connection as *secure. None of the traffic can be seen if the router is patched. The router will refuse to use the reset Nonce and the connection will fail. If the router is also unpatched then any unpatched devices connecting to it such as the camera may have their traffic viewed.

Krack forces nonce reuse which is specific to each connection.

*By secure I mean the link to the access point is secure. There is no guarantee with what the AP does or any network it forwards the traffic to afterwards (for example.. the internet). If you want end to end security use end to end identity verified encryption like SSL.

The attacker will only be able to view the traffic from the unpatched WiFi camera.

KRACK is a key reinstallation attack which, for each successful attack, affects the device being targeted and doesn't affect other clients on the network even if they are unpatched.