The 3 terminal blooms and the snaking of the stalk can probably both be attributed to frost.  That's usually the culprit here when those conditions occur.  I have an arilbred seedling that has 3 terminal buds for its maiden bloom, and an SDB seedling right next to it has 1 standard, 1 stylearm and 4 falls on its maiden bloom.  There is another pocket of 4 SDBs blooming and each one also has 4 falls, and one more yet has 4 standards and 4 falls.  All the rest of the SDBS, ABs, and other various bearded irises are just fine.  Some years, if the frost stops earlier, everything is normal.  Give that baby (a very pretty baby) another year to see what happens.