No, it is not pornography nor is it a joke. But yes, the huge object is exactly what you are supposing it is. The photos were taken at a festival called Hounensai, or fertility festival, which is among the few unusual but famed festivals in Japan. While at one glance this festival, which is held every year on March 15 at Tagata shrine in Komaki city, might come across as vulgar or indecent, it is actually nothing like that. In fact, it is a very important and dead-serious festival (how serious festival participants treat is another question, though) to pray for fertility, not least because the birth rate in Japan slumped to a record low in 2014. It is held in spring because it is when new life begins after the bitter winter. In fact, the shrine itself is dedicated to the same purpose throughout the year, inside which you will find numerous stones and objects featuring the male apparatus.
During the festival, a group of strong men will carry a mikoshi, or portable Shinto shrine taking the shape of phallus, a weighty one weighing a few hundred kilograms, and parade the streets, stopping from time to time to swirl it 360 degrees for a few times (to the excitement of parade revelers armed with sophisticated smart phones, cameras and selfie devices). In addition, women playing the role of miko, or shrine priestess, will also join the parade, cradling in their arms phallus-shaped objects for parade watches lining on the sides of the road to touch, the act of which is said to lead to child birth. Sweets and souvenirs of the same theme are also sold at the festival venue.
I do recommend you go and see for yourself if you have a chance.