Loki's symbol
Once known and spread throughout Midgard, this ancient symbol representing humans' perception of the God of Chaos is now all but forgotten - its memory only dwelling among history enthusiasts.
Under the impulse of a momentary emotion - on a whim, as Midgardians would say - Loki has etched this symbol onto Kara's skin. In ancient societies, this would have been a clear sign that she had been chosen by the gods for some unknown purpose; in turn that would have served to have her either praised as a blessing, or chased away from society for fear that she had been cursed by the gods.
It first appears in full description in "Entry #9" of Timeless.
The first Asgardian outfit Kara has ever worn; as instructed by Frigga, Tyra - who would later become Kara's handmaiden - offered the dress to the young Midgardian when she first visited Loki in the dungeons.
It appears in "Entry #27" of Timeless.
Upon her second visit to the dungeons, Kara wears a different attire - sadly it meets an untimely end at Loki's hands, though it is likely that Kara herself didn't feel that sorry for the beautiful dress.
The outfit appears in "Entry #29" and "Entry #30" of Timeless.
For the respect and love she bore Frigga, despite the short amount of time they spent together, Kara refused to attend the queen's funeral in Midgardian clothes and insisted she be allowed to dress as an Asgardian.
To this day it remains Kara's most favorite dress, in spite of the painful occasion that brought them together.
The attire appears in "Entry #33" of Timeless.
As Kara has an attire that she enjoys the most, so does Loki, who believes the combination of green and gold makes her look absolutely stunning.
"You look more ravishing in this than when you're naked, dearest." - to quote the Allfather himself on the matter.
The dress appears in "Entry #40" and "Entry #41" of Timeless.