You wont be able to see the valve open per se, but rather the rocker arms moving. Looking at the one photo you have the intake valve is at top of head and the rocker arm that opens it is to the top where you show a feeler guage inserted. Thats the intake valve. Rotate the motor and watch that rocker when it depresses inward and starts to come back is the revolution on the crank you need to check valves lined up at "t".