I recently shopped on line for a jacket that I thought would keep me warm & dry from LL Bean. Evidently, I bought the wrong one (this jacket is not warm at all). Also, it looks nothing like the pictures on their website. It just arrived last night.
Q: Am I stuck with it, or is this enough of a cause for me to take it back? (I am Not happy with it.)
You are never stuck with anything from LL Bean. They take it all back, no questions asked, whatever condition, no matter how old.
yes you are not going to have any problem returning it for any reason! If LLB goofed on your order they may even pay return shipping charges.
If you bought it online, there is probably a pre-paid return mailing sticker that came with it. With instructions on how to do it.
LL-Bean is great with that.
The short version of LL Bean’s return policy:
Did we sell it to you? OK, we’ll take it back. You don’t need a reason, but if you want to give us one we’ll make note of it for future improvements.
Oh, don’t have a return label? Call 'em up - they used to send one to you. These days they can probably email you one and you can print it out and tape it to the jacket. Well, to the package you put the jacket in, anyway.
Just don’t try to return it for spite.
Otherwise, you should be fine. 
They’ll take it back. Things I’ve returned:
A backpack. After four months, the zipper broke. I returned it and LLB sent me a new one.
Sandals. The sole of one came unglued the third time my husband wore them. He returned them and got 100% of his money back.
A dress. It didn’t fit. I returned it unworn and got the full price refunded.
LLB has great customer service and good quality merchandise. For the record, the number of items that my family has been pleased with outnumbers the returned items ten to one.
I’ve even returned a belt to them that didn’t have their label on it (presumably it was made by a different manufacturer but sold in their store in Maine), several years after I’d bought it, and they took it back, no questions asked. Their return policy is awesome.
To end out the thread, I found the return mailing sticker, I entered the code that it wasn’t anything like the picture, put it all back in the original packaging, duct-taped up the hole, & UPS’d it back. Thank you, everyone!