The brand has the word and in it like Frank & Oak. I feel it's easier and better to have a shorter domain.
Is hard to tell just like that. You can do some research online. Look up what searchers are currently entering into their queries, what does google give as possible search options... Do people search more as a conversation word1 and word2 ? Or without the and?
For online sharing purposes you might want a shorter domain but that shouldn't stop you from going with the longer one because you can get "shortlinks" created for Twitter and such, also length is not an issue if you share clickable links that don't have to be retyped by your potential visitor.
Your domain had to be SEO friendly... But also not an issue at the beginning, regardless of domain you will have to do a lot of SEO and marketing work to build relevance online so Google shows you in queries that don't include your direct domain name...
My suggestion: If your product or brand will be mentioned out loud or read a lot to include the AND then include that in your domain..