To be "all show" or "all image" would suggest something which is all about the outward appearance and not the inward reality. Oxford Dictionaries define "all show" as "An outward display intended to give a false impression."
"style over substance" fits the case well: it refers to valuing looks over content. It's a commonly used phrase (random example) but I can't find it in most dictionaries: EnglishBaby has a brief definition
The best expression would depend on if the place is particularly well-designed or merely draws the eye through lots of colours and decoration and fashionable things. There are other expressions for a place which is garish, ostentatious, and perhaps vulgar in its appearance with nothing of substance behind. This includes idioms like the British "all fur coat and no knickers" (defined in Free Dictionary as "To be attractive on the surface but lack substance underneath."), but this might be vulgar to some or obscure to non-British people.
"Showy" is somewhat similar - Merriam-Webster's usage note says "SHOWY, PRETENTIOUS, OSTENTATIOUS mean given to excessive outward display. SHOWY implies an imposing or striking appearance but usually suggests cheapness or poor taste."
"Meretricious" is defined by one dictionary as "seeming attractive but really false or of little value"; it originally referred to prostitutes, and MW suggests it typically refers to vulgar or garish displays, so it may or may not fit.