i agree 100% BP totty
Clothing is an external thing, however it is VERY symbolic. It shows who you want to represent yourself as and who you want to be. However there are many cases of pple who aren’t “black hatters’ yet very very frum. I know of someone who’s from South Africa who would wear sandals and shorts in the summer no problem -(VERY NOOOT yishivish) however they are very frum and have real yiras shamayim. When this person moved to E”Y they caught on right away and now dress the part.
However my opinion is that once a teenager girl/boy who comes from a yishivish home is already dressing differently, it is very significant, and it already has gone far. I know of someone who dressed totally yishivish and everythign who had REAL basic questions and struggled with yiddishkeit. There were no outer signs. B”H they sorted themselves out but once they are already dressing in a certain way, it shows they’ve been struggling for a long time, not a recent thing. I’m not talking about kids who want to be “with it” and cool. I’m talking more like – kids at risk