I'll try to be as concise as possible!

On Friday I uploaded an image from my favourite film 'Let the Right One In' onto my computer at my desk. The only other person to use this computer is the other receptionist who works weekends (the image featured one of the characters with blood on their face - yet this was obviously from a film as the title and directors name also appeared on the picture). This image appeared for approximately 5 seconds upon logging on and logging off again before diverting to the default company logo image.

Upon arriving at work this morning I receive a phone call from my line manager telling me that the weekend receptionist has left her a note bringing this to her attention and also outlining her 'extreme distress and upset'. It emerges that she's also reported me not only to my line manager but also the Internet Manager and the IT Department, as well as discussing this with several other staff members.

IT have since removed the image at my request. The thing that has upset me is that due to this lady's holiday I am working every weekend for the entirity of August and I just feel that she's stabbed me in the back (why couldn't she have left a note asking me to remove the image myself? Why actually 'report' me?)

I wondered about writing her a letter apologising for the distress caused (!) but also highlighting my disappointment that she didn't approach me directly. Advice?

Thanks in advance.
I can understand your disappointment and it is an awful situation for you to be in.

My advice is to not enter into correspondence with this person. She did not afford you the courtesy of asking you to remove the image which upset her - instead she made the situation 'official' and got others involved. She did not consider your feelings, only her own. If you write apologising, but cannot help mentioning your disappointment, she can use that as further 'evidence' against you and things may escalate. She is clearly not a person to be trusted.

When people behave like this at work it makes it very unpleasant for the rest of us.

Good luck.
rules are rules…why should she deal with you, when she can deal with the supervisor who can tell you to stop that…it's not her job to reprimand you.
aww babes xxxxxxxxx
man wat a ***** talk to her bout it i cant beleive she did that
Some people like to complain and start drama and bring attention to themselves. Perhaps her motivation was to make herself look good to the bosses, like she is a real crusader against misbehavior. (I dunno)

Perhaps this women has a trama from her past and the sight of a bloodly picture is a reminder of that trauma (doubtful but possible)

Perhaps she herself has gotten in trouble in the past for computer related stuff and felt that you having the pic was unfair when she's gotten in trouble (Most likely the truest scenerio)

I would just let it go. If you confront her even if it's to apologize, she could be crazy and see it as an attack and get you into even more trouble.
You have actually virtually answered your own question.

I certainly agree that it would have been far better, friendlier and diplomatic if she had either sent you a memo or contacted you directly to let you know the image distressed her,

However what is done cannot be undone and she decided to report the incident to her and your upper management.

I also agree that it would be an excellent and probably necessary gesture to write to the receptionist apologising for the incident and telling her that if you had realised that the image you uploaded and she saw was going to upset her, you would not have uploaded it at all.

Confirm to her that you have now requested that the image be deleted, and this has in fact been done,

You could also add that if she had told you directly that the image offended her that you would have immediately arranged for it to be removed.

Finally ask that she accepts this apology in the spirit intended and assure her that a similar incident will never happen again.

By doing this you are showing her that you are concerned, polite and caring, and there should be no reason why the receptionist should not accept your apology.

It might also be an idea to either copy the apology to the upper management who have become involved, or write to them separately telling them that you have apologised.

Good luck.

Poseidon
It would be one thing if you had engaged in activities that were blatantly illegal (inappropriate photos of children, etc) but this is clearly not the case. My gut reaction is that maybe she's sick of working weekends and would like to move into your weekly job position?

No matter what the motive is, I agree with Yer One. I would be very, very careful when it comes to interacting with this woman. She has already shown that any behavior *she* deems offensive or inappropriate will prompt her to involve upper management, and I think the same would apply to your reaction to this situation. Personally, I would act in a cordial, professional manner towards her, but I would distance myself a bit since she can't be trusted.
I don't know the film or the picture, but to be greeted by a picture of a person with blood on their face isn't nice, and could be a shock.Therefore you are in the wrong on that count. As the other receptionist didn't know you she had no choice but to report you to the manager. You could apologise, but I doubt whether she will accept it.
Write a quick note to her, apologising, and copy it to your manager. You cant really do anything else.