I'm in a small cabinet and bend all of my plants horizontal at around week 2-3 of Veg. (exactly like the picture you show). When trained this way, it seems to be easier to keep all of the flowers at equal height. (I top once or twice as well, but may not for my current grow.)
Here is how the buds look after training horizonatally---Notice that all the tops are close in height. This is key !
This is one plant grown with 100 watts of light. (sorry the bottom picture blocks the sideways training technique, but you get the idea) I use ties to secure the bend and a tie to make the actual bend.
To be honest, I cant understand why people grow xmas tree style unless grown outdoors. It doesnt makes sense to me not to bend the plant sideways. Light distribution is so much better when the plant is flattened out!
Sigh, I really need to check the post dates...this is a zombie thread. Lol