Animations will go down the straight side of the connector. When it reaches the end, it will continue on from the other side of the connector, like this:
I believe the current firmware supports up to 130 “pixels” (each pixel being an RGB LED). There are 8 pixels per foot, so this would mean a potential maximum of 16 feet with the current firmware. Since the T connector is not splitting the signal into 2 simultaneous strips, you would not be able to run 2 16-foot sections as this would exceed the 130 pixel maximum (32 feet would be 256 pixels). The controller also has a 2-amp limit and will automatically dim the LEDS if this limit is exceeded. Even if you could run more than 130 pixels (future firmware updates may be able to increase the limit), you would likely need an additional power inserter in order to maintain full brightness