If you're wondering whether you should watch the theatrical release or the OVA, watch this version, as it has a small extra scene where the stupid loli robot hits herself in the face with a rubber snake from a vending machine and it's cute.
Very emotional piece of work here by POP, a titan among men of character designers. If you like having your heart tugged on this will accomplish that and quite efficiently at just a half hour length. Flower is super cute and makes me envy the man of tomorrow, for we are a long way off from having our own little moe machines running around. Little anime, big impact! No reason not to give it a shot. If you're anything like me it will stick with you for a long time.