Looks like you have your transmission vent tube circled. Is this where you believe it's leaking? If that's the case check your primary fluid level. An over filled primary will leak from said fitting/tube. Also, attempt to tighten the fitting the tube is connected to. Not the tube clamp, it's crimped, but the fitting.
BTW don't you have a few threads going about a rocker box leak and engine cleaning?
1) clean that thing with some sort of engine degreaser. If you don't know what to use just ask your local auto parts store associate for assistance. Once clean you can see the source of the leak.
2) if you did post about rocker box gaskets leaking that might be run off from that area or I'm not seeing what you intended to highlight.