That's an instate declaration, Not a request for Federal assistance. That request for federal assistance is what triggers the deployment of gaurd troops from other states as well as national forces (regular army and navy and airforce).
She called on the interstate compact on Wednesday for gaurd troops from AR and TX, but as of Saturday had still not made a formal declaration of need to the Federal Government.
Do you know of a concise tutorial on "disaster law?"
The common wisdom perceives a balck and white system for all sorts of terms, like "calling up the Guard," and common sense indicates that there is a more complex substantive system. E.g., the LA Nat'l Guard was at the SuperDome before the storm hit, but more guard are coming in now, etc.
The official correspondence illuminates some of the complexity of the formal and legal mechanisms.