As screens don't have the same size on various devices, the displayed elements may not have the same sizes from a device to the other one.
The Online version is able to print what the browser accepts to print.
I just added a [font=courier new]@media print[/font] CSS query to print only the plan and the 3D view, but only Safari seems to generate a correct page, other browsers giving more or less nice results.
If you want to print at a given scale with a more predictable result, you should print with installer version.