While watching old snooker matches, like the famous Higgins vs White match in 1982, I notice that the breaks seem to be like straight pool breaks, with just the corner balls moving. Ideally, the two corner balls go to the rail and return to their place in the pack. A typical safe break in straight pool is show in this video at about 1:45.
In modern snooker, however, break shots seem to cause a lot more activity. Is that because the balls are racked loose to prevent perfect breaks, or is it the modern style to allow more balls to come out as an "aggressive safety", or some other reason?