it is clear that it is your game and it is your rules, but you place a description of the rules in which you do not exclude the images, besides, I think that the people that use images do it to leave a better and more specific idea of the object that we speak, and even more so when our native language is not English,
everyone does what his reasoning dictates, but I think it is very wrong to eliminate a person by placing an image, makes the person look like a rag what is in very bad taste
And did you consider the other side? Taking out the fun for others? The whole point of this is fun not money or winning... so I think if you look at the general point you'll come to see everyone's gaining that way.