Several times in the series the holographic observer (usually Addison) is able to sit down next to the leaper (Ben), as if they are in the past with him. This shouldn't happen since the imaging chamber doesn't have a seat in it. Technically the observer should phase through the seat they are trying to sit on.
At various instances, Addison is seen to cast a shadow while interacting with Ben in the past. Since she is a hologram, this should be impossible.
Just like in the original series, Addison does things Ben physically can't or isn't present for (such as look on the other side of a wall, following someone who isn't with Ben etc.). Since the Imaging chamber is tied to Ben's brainwaves, logically the hologram should only be able to see and hear what Ben does since they aren't actually in the past. It would be like trying to see beyond the edges of a photo.