I am very glad you posted your beautiful watch and bracelet! I have a 19mm WG Lange bracelet but haven't attached it to a watch. I took this pic over a year ago but never decided which watch to use with the bracelet (the one on the left is a blue-dial sibling to yours):
Here is that same blue-dial watch in two different lighting conditions:
And to answer your question, I think all Langes look good with jeans and a t-shirt, since that's mostly what I wear.
This one looks particularly casual/informal on either a bracelet or a strap:
Thank you again for posting those great pics!