Unusual to source Thai girls for a trade show in HK. Maybe the exhibitors brought them in from outside HK which would mean they need a tour guide in HK...you.
I would think it would be cheaper and easier to find local HK girls who can speak Japanese, English, and Chinese.
But I do admit the girls (not the promo girls) that work in the booths during the Fashion, Jewelry, Cosmetic, Healthcare, Hotel, F&B, etc can be quite attractive.
Sure there are nice promo girls (models and cuties) during the Anime, Electronic, Computer, and Auto shows, but it is so hard to get close to those girls as they are surrounded by alot of skinny geeks with their big cameras.