I see this gentleman often at Pitti and he is always beautifully dressed.I love the sleeve length, pant length and overall fit of the jacket. The slimness of the jacket and pants actually creates a lengthening effect. I would maybe try a slightly more narrow tie and smaller collar on the shirt but that is personal choice.
Notice the upper sleeve, over biceps, section of his jacket - I always try to get that sleeve section a slight bit more narrow. It really finishes off the overall long, slimming effect of a slim cut suit. Look at Astaire, his sleeves in that section are always very narrow. It is a very small detail but one that always stands out to me when I watch Astaire movies.
To the opposite effect, if you are narrow this is a good spot to create a wider visual.