Significance of the Secret Room in the White Palace? (Spoilers obviously)

[Sareve]

To the left of the final hollow knight "magic statue" before you reach the King, there's a bit of the floor that you can break. It doesn't have that usual cracked floor sound when you walk over it, but you can see that the floor is cracked compared to the rest of the level.

In it there's some sort of forge and mirror or something, but what is the significance of this room? I can't seem to do anything in it, and it doesn't seem to be related to anything else that I know either.

[Kein Zantezuken]

There are 2 rooms, both serve lore purpose: one tells us about King's ability to shape void and another is a possible sequel hint that points out KIng and White Lady had a child?

[4thQueen]

The Hollow Knight, and by extension the player character, is implied to be that child. While obtaining the Void Heart, there is a text passage to the effect of "Soul of Wyrm, Soul of Root, Heart of Void" that is in reference to yourself. Wyrm would be the Pale King, Root would be the White Lady.
Contrast with the more, ahem, traditional child Hornet, born simply of Wyrm and Beast. Though her title as "The Gendered Child" might have some significance that escapes me at the moment.