Brassia has changed its growing shape

[shanestaunton]

My hanging brassia is now growing tall where in the past it has taken up the sides of the pot. It looks like its growing away from the sides and growing taller instead. It has flower spikes as usual [10 to 15 in each pot] but I am a bit intrigued about why it has decided to grow up this year instead of out. I can take a guess at things but would like to know other peoples ideas. Thanks in advance.