This door separates a sunken rec room from a den. It has always struck me as odd that there is trim/casing along the bottom. Is there a better way of handling the trim around the sides, but with no trim at the bottom? Perhaps a stair nose with notches on the sides so it extends to the width of the casing on the sides would be a better choice? I’m looking to either validate that this was already handled well with the trim, or to identify a more typical approach.
I tend to agree that this door would look better if there was a threshold in the bottom of the door opening that included a projection nose out just a smidgen beyond the side casings both in overall side to side length and beyond the surface of said casings.
A door opening like this is a bit of a safety hazard and really should have a "landing" on the low side so that when you are concentrating on getting through the door that you do not get a surprise step up or step down at the same time.