The movie probably have side story segment (like pokemon movie)
Spoiler for lina stuff:
This first two part look like event from early volume 9 in Visitor Arc.
Wait, she suppose to be in Parade mode infront of staff member right
henchman / amphibious operator? look weird....
This is the new one, USNA mobile suite(really look like American concept) and Brionac Normal form???(wow that a magic rifle, finally Satou use this)
'Air to Ground??' who become a target???
Lol, this amphibious vehicle got extra 'railgun' fire power
Lina take off, wait where her weapon???
Spoiler for 'Shiba Tatsuya will become a legend!' = Maheswara stuff:
This exactly from anime 1st episode, scene from battle in okinawa (that heavy sniper Rifle)
so basically this is prequel part of the movies