The magnifying glass is a projector without the collimator so the picture will be upside down.
The focalpoint is actually a plane and not a point so a ledmatrix will be projected as an image.
It works better than a straw because it collects the light instead of blocking it.
The projected image brightness will be dependent on the distance since all of the light in a single led is averaged over the size of the projected dot of the led.
I have built a number of led discolight effects using this and it works even if the room is not dark.