Is showing off a form of hypocrisy, and does it fall under the Hadith: "Whoever prays to Allah for forty days in congregation, catching the first takbeer, will have two clearances written for him: a clearance from Hellfire and a clearance from hypocrisy"?

Riya' (showing off) is a deed performed by a servant for people to see. It is a minor shirk (definition), and its perpetrator may be a disobedient believer, not necessarily a hypocrite. As for Nifaq (hypocrisy), it is outwardly displaying faith while inwardly concealing disbelief. Thus, every hypocrite engages in riya', but not everyone who engages in riya' is a hypocrite. Nifaq is more comprehensive than riya'. The cure for riya' is through supplication: "O Allah, I seek refuge in You from associating partners with You knowingly, and I seek Your forgiveness for what I do not know."