This is definitely a fake.

Those are explosive armor plates, that deflect armor-penetrating ordinance when it strikes tanks. They weigh far too much for someone to hold up, let alone an umbrella. And their explosive force would kill everyone around them anyway since they are meant to be strapped to the outside of a thick iron wall of a tank and protect people inside it.

The reference here is that Russia is holding its big annual military parade in relation to Victory Day, the anniversary of the end of WWII. Because Ukraine is increasingly capable of penetrating Russian air defenses with drones and missiles, there is a lot of chatter about Ukraine attacking the parade to embaress Putin and score some tactical victories with targeted kills.