Water or oil seeping in. The engine is caked with spilled oil. There's a rubber gasket there, maybe change that out.
That looks like dried residue from rusty water. My guess is that water is or was leaking from the hood to wiper cowl area onto the engine. Posted via the PriusChat mobile app.
That gentlemen was caused by a sparkplug that did not have a compression ring that vibrated loose. Have put about 7000 miles on this car since I bought it. Was able to remove the #4 plug with a socket and extension with my fingers no wrench needed. Was sure threads and therefore engine was shot. To my surprise sucked out the raw fuel and torqued the new plug in to 13ftlbs no problem. All new coils and ran 100 miles last night and it's running strong so fingers crossed
This is awesome, because the first thing I was going to ask was whether the sparkplug was loose. Had a slightly similar experience when a customer was having problems. He had recently replaced his plugs and tightened them by feel, even though he had insignificant experience of what 'feel' should be. All four came out practically by hand.
