I believe that gap can be adjusted through the clips/bracket that holds the door up, unless it wasn't hung right or with the correct sized brackets. You don't have flooring yet, so they might need to be raised up a touch to clear the floors, which I assume will be tile.

That looks incorrect to me. We have some pocket doors and they go up inside the pocket by a small amount. I would revisit that with the contractor.

Your door should look like these pocket doors.

A piece of trim can be added to cover the gap, but if the door leads to a gas chamber it may inhibit ventilation.

The door doesn't look level to me.

Our pocket door has a small bit of extra trim to cover the gap

Looks like the door frame isn't square. Put a level on the left side (check for plumb) and on the upper inside (where the door is hung from) and see where it's out of level.

something isn't square

Obviously the gap shouldn't be visible. do they plan on adding any trim to cover it?

I had to go look at pics on how we did ours

Here's another one from another job that hasn't been painted and trimmed out yet.

There is another layer that makes it appear recessed when done. Typically we'll use a piece of doorstop. Once completed the door, jams and casing should all be plumb and square.

Perhaps they aren’t finished yet. Worth asking how it will be completed

Thank you all so much, I really appreciate the insight! Going to make sure to ask the questions mentioned above and see if we can’t get it looking more like the beautiful examples you shared.