Landlords won't generally let you make structural/material changes to a floorplan without a longterm lease to justify it. However, you can make some pretty snazzy temporary office space that doesn't require permanent modifications to the space using privacy walls and glass partitions[1].
From a structural standpoint, they're basically fancy cubicles, and made by the same companies as standard cubicles. The most damaging thing they do to the structure is mount the tracks for the glass into the floor and ceiling. But that's usually considered normal wear and tear since it's easily fixable on move-out.
From an aesthetics perspective, they're effectively mini offices and can be done very well, making a space look nice and chic and making employees a lot happier. All with what amounts to some fancy cubicles.