When you receive a notification on the lock screen, you get a bubble-styled notification. As you receive more and more notifications, your notifications begin to stack one above the other on the lock screen as flat list view notifications, and not as bubbles.
If you would like your lock screen notifications to appear in the flat list view all the time, rather than bubble notifications, a new free jailbreak tweak is available in Cydia called LSFlatAlerts by iOS developer magn2o.
The list view is a better view than the notification bubble view because rather than seeing a bubble that shows your most recent notification, and then having to pull down on the grabber to see previous notifications, you will be able to see all of your notifications right off the bat in list view.
LSFlatAlerts doesn’t come with any options to configure; just install it and you’ll have list view notifications on your lock screen from now on instead of bubble notifications. If you would like to give the tweak a try, it's available for free in Cydia's ModMyi repository.