Have I ever moved something to read an inscription? Sure. So don't think I'm going "holier than thou" on you. However, I try to remember that more often than not, things were placed on that gravestone with purpose, love, and care.
I do want to point out a pet peeve of mine, though. I shudder to hear of rocks being removed from a gravestone. I do NOT remove rocks from gravestones. Even those little pebbles that are most likely gravel accidentally kicked there by a passerby. Remember this: Rocks often signify a visitor to a particular grave. That rock someone chooses to remove in order to "clean up" the stone and/or photo might've been put there on purpose. I think moving them is incredibly disrespectful.
Sometimes all it takes is a couple of photos or a different angle of your camera shot to get the entire inscription. Not all photos have to be taken "head on." The following is a simplified example, but you can get the idea.
Louise Malone Sadler's tombstone photo #1:
Louise Malone Sadler's tombstone photo #2:
As you can see, between the two photos, the complete transcription can be read:
June 13, 1925 - Sept 12, 1990
So I can honestly say, No flowers were harmed in the filming of this gravestone. :-)