On a trip to London in August, I noticed that all the burka or black-clad women Moslems were shopping on Oxford Street. When you got to the City, where business is done and people actually work, there were no Moslem women to be seen.
One observation does not a trend make.
Take several observations over time to discern the trend. Londoners see it, tourists may or may not see it depending on their frequency and locations of visits.