TBH, I find this slightly prejudiced. If this had been a picture of a Canadian, or American solider, or even an average Joe with a weapon this would not have been an issue, but since it's a Muslim, it's automatically assumed "terrorist". The individuals in my avatar pictures are members of the national armies of Muslim countries or in some cases local police forces and have absolutely nothing to do with terrorism. I choose these pictures because they mean something to me, just as others have pictures of flags or soldiers, so please, try to be a bit more careful about categorizing Muslims as terrorists.
Sorry, no intentions to criticize your choice, just making a personal consideration (that can also be wrong, i admit this).
I think that is not matter of showing weaponed peoples, that make the difference, is, probably, the context of the image ..... i mean, any image of soldiers with weapons, make no wrong impressions, cause, unconsciously, peoples associate soldiers and uniforms with war and weapons, so is just natural to see a soldier with a weapon in hand ..... where instead, showing a civilian, woman, pointing an RPG somewhere, don't gives the "right" images association, for the unconscious .....
Also, i admit, there must be some part of "public brainwashing" ..... medias always associated the images of muslims and weapons with terrorism, so for some peoples, is automatic, sometimes also not conscious, to associate the image of a weaponed civilian dressed as muslim with terrorism.
I personally don't find it disturbing, also cause for me is clear that is just an advertising pose, not a true terrorist (shooting in this way an RPG, you lost half of a hand, LOL), but some other peoples can feel it disturbing just unconsciously, for the actual context .....
Like, as example, what if i post a pic of a medieval knight half covered with blood, waving a blooded axe, with 20 or 30 other peoples around killed, ripped and eviscerated ? ..... in the actual context, is surely disturbing, cause now we're used differently, but in that age, it was a sight perfectly normal, and none may had any reaction, if not maybe, to not walk in the blood for not dirt their shoes ..... or in the Japanese Edo age, where a samurai was never thinking to attack an opponent without present itself, exchange salutes and all the courtesy forms, and at the same time, the same samurai had not the minimal hesitation in cut the head of the first villain passing around just for check if the cutting edge of his sword was refined good enough, and none had absolutely nothing to say, seeing this ..... different contexts ..... is this, imho, that make some pics disturbing for some peoples, not just the pics themselves, but overall the context (but, as i said, it's just a personal idea, and can be wrong)