"99.9% of people carry smartphones nowadays, so it's not like you'll stand out as a target. "
I feel Stacey deserves "co-winner" status with Roberto for this comment. Of course, as a tourist you are more of a target (as is often said, locals can always tell who the tourists are, and while most locals don't care, thieves do, since they know tourists will be moving on soon). But just showing a smartphone won't make you stand out in any way.
I'm now in Israel (not in Europe, I know), and I can say with confidence (and some amusement) that I would stand out if I DIDN'T brandish my smartphone at every opportunity (on the train, in a restaurant, etc). This is doubly amusing to me since I had a flip phone until 6 weeks ago; I'm so glad I haven't had to suffer the embarrassment of not being in style! And if you want to be in fashion in Israel, the larger "phablets" are clearly preferred. I've noticed for some time that there are definite fads and fashions in cell phones, which vary by region. In New York City, the iPhone really dominates, but only a few have the larger 6 Plus; here in Israel, iPhone and Samsung are about equal, as long as it's the largest model.
So if you want to blend in and be mistaken for a native, forget clothing - bring the "it" phone for your chosen destination, and no one will be the wiser!