I'd have been happy with any level of visual fakery, and if more complex = more expensive and this somehow hurts the show, that's not cool. But I like pretty, and what we have is pretty.
The scene is cute, but with obvious problems inherent in trying to make cute. If the ship can't sense the heroes with her fine machinery otherwise, how could she spot the delta? There's a sandstorm raging and all - visual cues would be the most futile of all.
We don't know whether the landing party needs to convey "Here we are!" or "Pick us up now!", though. The ship could and should have a pretty good idea of where the two are, but it might not have occurred to them up there that the party wants to beam up. In that case, though, Georgiou should just wave her arms - surely that would be more or less as visible to orbit as the delta?
No point in speculating in detail, tho, as we're bound to get a preceding bit of dialogue setting up the situation. Although not necessarily a long one - it's perfectly possible this is the very first scene in the entire show.
Timo Saloniemi