Q:

Innocent Gifs from Inappropriate Sources

The tense of verbs may be obfuscated and my point of view in the post does not necessarily represent my actual role. 
The team culture I am a part of is quite relaxed and lots of communication happens with images and gifs. Some sticky situations have occurred where an individual shares a reaction gif or a still image including a questionable person or from a non-work appropriate source that caused offense to the receiving party. Most, if not all the gifs used, come from Giphy where a person types something innocuous into the search bar like "Thanks", or "Party", or "Great Job"
Examples (Person A/B are not necessarily the same person in each): 

Person A sends an email to a DL with an alert and shortly after replies with a "Whoops, nevermind!" As a response, Person B sends a Donald Trump "You are Fake News" gif. Someone on the DL is by no means a Trump fan and finds the gif inappropriate due to his policy and him as a person.
Person A sends a normal every day email and Person B responds with an innocent gif indicating an affirmative response. However, the gif is from an R-rated movie and the scene immediately following the 2 second gif is wildly inappropriate work the workplace. Person B says they are not familiar with the movie it came from, Person A is familiar with it and takes offense because the following scene is quite crude.
Same scenario as the previous list item, but the gif was a "Thank You" gif, and the person in the gif is an adult film star. Nothing inappropriate in the gif whatsoever. Again, Person B claims no knowledge of who the person is, found it on Giphy, but Person A knows who it is and finds it inappropriate. 

None of the gifs in question, in their isolated state, are offensive, demeaning, etc. With more knowledge about their source, it is understandable that it could be inappropriate to receive a gif like that. 
I need to mediate the situations at hand and keep in mind culture while upholding standard company policy (no porn in the workplace, keep politics in your personal time, no NSFW stuff on your work computer, etc.). It seems to be a tricky situation because people are claiming to not know the source of the gif material. I would rather not trash my team/department morale by not allowing them to have some fun and send silly gifs/images/vines to each other, but I absolutely want to make sure people feel comfortable and safe at work. 
Would the best course of action be to go the totally safe route and say to keep it professional and get rid of the gifs/pictures in emails, ask people to know and understand where the gifs/images they are sending come from, or to say that the gifs in their current state do not violate any policy because they do not contain any inappropriate material for work? I am looking to balance legal exposure, morale of the team/individuals, and individual feelings of those who may be more sensitive/buttoned-up than others.
Technical clarification: The gifs are sent through communication apps, like MS Teams, and auto play in the communication channel due to a built-in integration with Giphy, or they are sent as links in email/chat to sites like Giphy and replygif.net

A:

Disclaimer: Completely opinion-based.
I would allow all of the above things, assuming they are not otherwise NSFW.  I feel like your coworkers are a little bit too sensitive and need to lighten up a little bit.
That said, this seems like a question based around company culture, and company culture is driven by the members of the company; if the employees of the company do not like that gifs are being sent around in jest, then perhaps you (the plural "you", i.e. everyone who is doing it, not just you specifically) should stop doing it.  That said, if most of the people have fun and are joking around, and it's only a select few people who are raising these concerns, then as a manager (since it's your responsibility to mediate, I presume you have some level of authority in the company) you might want to reconsider whether or not these people are the right fit for your company/team, culture-wise.

A:

It sounds like this is a situation where one person isn't comfortable with the casual nature of internal communication - which is a risk with any company as it grows. 
In terms of how to deal with that situation, there are really only two options: The first is to require a more formal approach to internal messages, which would mean a companywide email detailing that GIF is not an appropriate format for office communications and must no longer be used. 
The second is to speak to the specific person who is taking offence, and tell them that the casual nature of communication leads to a generally more friendly and relaxed working environment, which is generally better for everybody. It's unreasonable to expect everybody to know the surrounding context for a GIF, so the company stance is that the offensiveness of any message is judged only on the content available within that message. If you have to research the source before you can find it offensive, it's not offensive. 

A:

On it's own, a GIF is just a GIF - it has no deeper meaning. Your person A in all situations is associating those GIFs with other meanings or values which are not directly being communicated.
If it is not NSFW (literally), then generally, it should be appropriate for the workplace.

