Does Miami look like it’s in a foreign country ?

The first thing you need to understand is that people who have never been to Miami before tend to confuse Miami with Miami Beach. The two are very close to one another geographically, but in terms of the aesthetics and the demographics, they're completely different. Yes, there are a few places in Miami that are fancy, lots of steel and glass and opulent homes and stuff like that, but for the most part, Miami is just like any other sizable city - it's got its own neighborhoods and the same problems all other cities have with traffic and crime and pollution and all that jazz. Miami Beach is much smaller, the populace is much wealthier, much whiter, much more Jewish, and a lot older. Miami is a bit different from many other sizable US cities because where places like Atlanta and Philadelphia may be MOSTLY black, but there are still plenty of whites and Hispanics/Latinos, and Asians, etc., Miami is almost exclusively Latino and predominantly Cuban. There are dozens of cities all over the US that are Latino but predominantly Mexican, but the fact that Miami is so heavily Cuban sets it apart. It's true that there are plenty of parts of the city where all you hear is Spanish, all the signs are in Spanish, all of the businesses cater to Spanish speaking customers and all of the food is Cuban food, but that's not the whole city by any means. There are plenty of Americans living there. There are black ghettos and middle class white neighborhoods and a normal, stereotypical downtown. It's not a foreign country by any means.  

No, it doesn't look like a foreign country.

WalMart, McDonalds, Home Depot, Starbucks, CVS, naaaah. The WORLD looks like USA.

No, not at all. If you're trying to make a negative comment on the number of Spanish speakers there, you should know that I have been in a lot of Spanish-speaking countries and no city in any of them looked anything like Miami. Miami has a flavor and culture all its own. All around the world, there are fabulous cities where people from many language groups mingle. Only in the US is that seen as some kind of negative. 

No. But what if it did? Have you ever been to another country? I doubt it.