Is this the first Aishti ad? Well, naturally I cannot be certain, but there is a probability it might be among the first. It was published in Annahar newspaper in 1991. You will note that back then the old logo still stood, and that the boutique had two branches only - one in Jal el Dib on the bifurcation of Juicy Burger (a defunkt Lebanese burger joint), and one in Mar Elias behind Banque Mediteranee (likelihood the same bank branch still stands but has been rebaptized as BankMed). See? We are far from the luxury behemoth which is now present now just in several places and stand alone boutiques in Lebanon, but also in many other country (Jordan, Kuwait, and the UAE).
Once more, I tried to track other ads in the same time vicinity in the same newspaper, but could not find any. I tried to see if one year earlier there was anything, and no luck. Which is why my speculation was that this could be the first ad for the brand.