To answer the questions in the brochure:
"Is your dress and grooming modest?" Yes. If your shoes are in good condition and not outrageous in style (running shoes are probably not), that is not immodest. Blue slacks are not immodest, and the clean-shaven look is what they expect. A light blue polo shirt is appropriate--if it is properly fitting, in good condition, and not stinky dirty. And, in summer, such a shirt would be better than a dress shirt that is going to get stinky dirty in a hurry in the heat. Polo shirts are plenty modest for many workplaces--I have been seeing more and more employees dressing with polo shirts or similar styles as part of their uniforms, in public service. If this was immodest, that would not be the case.
"Does it reflect well on the God I am worshiping?" Well, does the God you are worshiping want you to be reasonably comfortable, or does He expect you to be hot and miserable? If the attire is clean, in good condition, and fits properly, this attire certainly should reflect well on any reasonable God (I am not claiming here that Jehovah is reasonable). If any God is so unreasonable that He wants you to sweat and be uncomfortable, is He really worth worshiping? I could understand if you had ratty sneakers with shoelaces untied, shorts that were way up to your privates or pants that were halfway down, baseball cap on backwards, or a sloppy hoodie (or if it was so dirty that it stinks). But, regular attire (that you can wear in most service departments at work) is not unreasonable.
"Would others be distracted or offended by my appearance?" Probably not. Many people wear running shoes--they are more comfortable than dress shoes. Walking shoes might have been more appropriate functionally, but not appearance-wise. The slacks and shirt are not out of the ordinary--if people can and do wear them at work, how can they be distracting and/or offensive? I would be more distracted by inappropriately "well dressed" people, especially on a hot summer day and especially if they were sweaty and stinky. I would be more distracted and/or offended by attire that was blatantly uncomfortable or that could result in injury.
"Am I setting the proper example for those visiting for the first time?" That depends on the rules--for visitors, the above attire is not unreasonable. Most first-time visitors, particularly worldly people, are not going to show up in suit and tie. And, if I was visiting for the first time, and they told me that I needed suit and tie to just visit the factory, I would probably not be attracted to the religion. However, I would be more impressed by reasonableness if I saw people dressed in neat business attire or attire that is common in workplaces. I would not accept dressing up in a sloppy hoodie (unless it was very cold out), clothes that are in very poor condition, pants that are halfway down, a baseball cap on backward, smelly and sloppy sneakers that are not tied, and skimpy attire that may be more appropriate for the beach or amusement park than a factory. And I would not like people to dress in ways that are unsafe (bare feet, no shirt, no pants where they may protect against injury, etc.) But, if you can get them at a place like L.L.Beans and they are similar to attire that is proper and acceptable for uniforms in the service sector, wearing it could impress people on reasonability.
And I am sure other businesses are not offended by wearing out-of-uniform clothing (that is modest) for visitors. Supposing I were to visit L.L.Beans with clothing made at Wal-Mart. Chances are good that they would accept that (as a visitor). Or, if I were to visit a factory owned by Wal-Mart dressed in L.L.Bean clothing--I doubt that either would be offensive. And both are worldly companies. If worldly companies will accomodate these differences, I would be quite offensive to have "the truth" being intolerant of wearing non-offensive clothing that does not meet the uniform policy as a visitor.