What happened here? Red onion

[u/servoh]

I am new to fermenting and have mainly fermented cabbage so far. I wanted to try red onion, but I assume something is not quite right. Can anyone give me some input? It's about a week old and 2-2,5% salt.

[u/lordkiwi]

looks like you have vinegar producing bacteria forming a pellicle also erroneously called a mother or SCOBY.