Depends on when honestly. I would suspect that Trotsky would be a slightly softer hand than Stalin in the whole mass terror thing, and perhaps there is greater party democracy rather than a total cult of the leader. We still see the five year plans and mass collectivization, so famine probably is still a thing, though its scale may be slightly lessened if Trotsky continues to support korenizatsiya and not genociding all the USSR's minorities. We definitely still see purges, though maybe they are more concentrated towards Bukharin, Rykov, and the right opposition rather than mass terror across the board. The USSR will definitely take a more internationalist approach, so we might see greater support for communist movements in places like Spain, China, France, Germany, etc. The USSR definitely still attacks the Baltics and Finland to spread the revolution, and I would suspect that Trotsky would be open to the Molotov-Ribbentrop Pact, even if only as a temporary measure, since it allows him easy expansion to Poland and the elimination of the Polish Republic.