It really pains me to spot a galaxy like this in the archive. This is just how the old WFPC2 did things. You need at least two different frames to complete a larger object but there's a whole bunch of them that only got one so they all look just like this.
NGC 3433 is almost perfectly symmetrical. It's so symmetrical you could clone the data, rotate it 180 degrees to cover just the black L and it would look like a complete galaxy with minimal touch-up to make brightness match. It was tempting to upload a version like that but it would be way too easy for the image to be taken out of context and for people to think that the data was actually there when it's really just cloned.
I increased the saturation to create a greater range of color. I also increased the sharpness of the dust so you can see more details.
North is NOT up, it's 37.7° counter-clockwise from up.