If I untag a photo my friend has posted, does that mean only her friends will see it?

While I'm not generally sensitive about how I look in photos, I find some of the ones my friend posted very unflattering. As well, my dear departed parent would likely not want to see herself in her latter stages of dementia if she could see her photos from the heavens above. Then there is the issue of how long these photos should stay posted. At any rate, I have removed the tages, so I don't see them and I ume my friends then do not see them. However, as long as they remain posted by the originator, I ume their friends can see them. Am I correct in these last two umptions?