Copying a vector to a vector requires the global sizes to conform. Depending on whether or not the vectors are aligned identically to the template vector, this becomes a local copy or an operation that shifts (rotates) the data to achieve the new alignment. More on this later.
When copying a vector to or from a projected vector, there are two cases that must be addressed: When the projected vector is projected onto column of nodes, the global lengths of input and output must match. When projected onto a row of nodes, the global length of the vector must match the global width (after projection) of the projected vector.