O operador <<<
é uma string here
Dado:
[n]<<< word
The word undergoes brace expansion, tilde expansion, parameter and variable expansion, command substitution, arithmetic expansion, and quote removal. Pathname expansion and word splitting are not performed. The result is supplied as a single string, with a newline appended, to the command on its standard input (or file descriptor n if n is specified).
Para traduzir isso para a concha de peixe, você provavelmente faria:
echo '{"some": "xyz"}' | jq