The cemetery can only dictate what is placed on the grave as stated in the deed. If no restrictions are listed, you are free to use any memorial you choose.
The two sentences above do not relate to one another. The cemeteries describe exactly the parameters they will allow on the grave in terms of what flowers, fences , borders or bushes are permitted. Anything outside those parameters gets booted
The MEMORIAL is another thing. They usually describe precisely what type ie. flush, brass marker, slant, upright, monolith etc they will permit plus the type and quality of stone, the height of the stone the width of the stone and the thickness of the stone. Deviate and it gets booted. All of this is meant to prevent the ugly trashy ghetto-izing that occurs when people can do what ever they want. (And MAN it gets out of hand fast) In the case of this story the pic looks like they specify flush markers in the section since no stone is visible.
“The MEMORIAL is another thing. They usually describe precisely what type “
And if they don’t you are free to chose what you want.
“The two sentences above do not relate to one another.”
They both are true and both relate to plot deed restriction and what the cemetery will allow.