I imagine the Portugese communists operating somewhat similarly to Castro and co over in Cuba. Theirs may as well also be a red island in an otherwise capitalist region, assuming Spain and the other Western powers don't intervene to crush the commies. Assuming they manage to stay in power, it'd give the western leftists a bit of a morale-boost, despite the certain pro-Soviet leaning. If Cuba's reputation is any indication, a leftist state born out of a homegrown revolution (even if it has active KGB assistance) is easier to sympathize with than the satellite governments imposed on Eastern Europe.
Foreign policy-wise, they'd still seek to have active influence in Africa - especially with their former colonies, though I'm not sure how the locals would take to that. Getting extra help from their ex-colonizers in the fight against Apartheid South Africa (and in "maintaining order" within their borders) will have some interesting effects on Angola and Mozambique. Further afield, Macau could end up back with China a lot earlier than OTL, depending on China's relationship to the Soviets in this scenario. Unfortunately, East Timor will still be a target of the Suharto regime in Indonesia.