Best to confirm this with an alim and I'm just passing on what I have researched over the years. As far as I know pictures in a room/pocket do not invalidate one's salah like some things instantly do e.g. not having wudu or breaking one's wudu during the prayer etc. Basically pictures are not one of the well-known invalidators of salah.
Also it (that is a 'picture-free' environment) does not seem to be mentioned as one of the well-known pre-requisites for salah such as : a clean area and clean clothes, puberty, sanity, being a Muslim etc. I have never heard of the area needing to be totally 'picture-free'. The other thing is we have to be sure is something is halal, haram or makrooh (disliked) for example. So pictures in the prayer room maybe disliked but not haram.
I understand that scholars have pointed out that certain pictures/picture making is necessary (or already in place and not in one's power to change) such as : passports, money, photocard IDs etc. So you are not to blame as this is forced upon you.
Also we are instructed to not go to extremes in our deen and make life too difficult (or too easy). In todays world pictures are almost everywhere.