I have restricted some friends on Facebook from seeing a picture I posted on my timeline. If a mutual friend liked the picture, can the restricted friends see this on their timeline?
If you post something on the internet you should expect that it has potential to be seen by everyone. But since your question is specific to "restricted friends" seeing things in their timelines... Though "No" may sound like the correct answer there is a way for the answer to be "Yes".
Let's say that you and I have a common "friend" (we can call George), I post a picture and restrict you from seeing it (but not George)... George likes the picture and saves it to his computer, then uploads it to his photo album sharing it with you.
It is now showing in his timeline and you can see that image that I was restricting from you.
Had "George" not taken the extra step, Facebook would recognize that I didn't want you to see the image and would always prevent others from sharing it with you.