Pickle in the UK has a split personality as I think @karadekoolaid will confirm.
Congrats,
Herbaceous ! Well done indeed!
Even though I don't eat steak, that recipe looked delicious and was beautifully plated.
So pickles. Since I've spent the last 25 years pickling everything in sight

I'll just add my experience.
In the UK, you have these delicious condiments which are a mixture of fruit, vegetables, vinegar and sugar. Branston pickle comes to mind; farmhouse and Xmas pickles as well. There are also straightforward pickles (in vinegar) such as onions, eggs, red cabbage, beetroot and walnuts.Then there are chutneys which, although originally from India, morphed into a standard English condiment (Cheese and chutney sandwiches for High Tea?).
Indian pickles, however, (achaar) are fiercely hot, salty and often acidic, as in Lime or Gooseberry pickle. Totally different technique, but the end result is the same; to add a touch of je ne sais quoi to a plated dish.
Middle and Eastern European pickles were obviously designed to preserve fresh , summer ingredients for the winter. Gherkins/cucumbers/cauliflower/mushrooms/turnips - all available, pickled for the winter, often in brine.
Middle Eastern pickles are usually preserved in brine and often include root vegetables or cucumbers.
East Asian pickles are, in a certain sense, quite the opposite of their European counterparts, since they're frequently "quick-pickled"; although things like Chinese preserved vegetables are also pickles.
I'm not sure, but I believe there are pickled meats in the USA.
Purely from a practical point of view - do you want to include (a) chutney (b) Indian pickles (c) pickled meat in the challenge? Totally up to you!