ETA: however, it occurs to me that the artist could have simply capped the shot himself from the DVDs, which is why you can't find it at TrekCore. When a fan site caps images, they tend to concentrate on the series regulars, rather than the guest stars. I'm sure it's possible that shot was from the ep, just not in a cap in the TrekCore galleries?
That's far more likely than it being a composite image. In fact, I do find the image familiar.
But recall that we've identified some of these images as being taken directly from TrekCore. The shot of the Enterprise
on the TCoK cover is precisely the one at TrekCore from the end of the remastered "The Man Trap." The perspective on everything is exactly the same, so it has to be that very frame. The Kirk and Spock images on the Inception
cover also seem to be the exact same frames found on TrekCore. So that seems to indicate that the cover artists are using that site as their sources; thus, it was reasonable to expect that the Leila image would come from there as well. Hence my surprise that it apparently isn't.