The pipe character (|) indicates a semantic cluster. A semantic cluster is a sub-section of text that is to be semantically analyzed by itself. You have two semantic clusters in your example title tag.
While the pipe character is not the only punctuation that indicates a semantic cluster, for example a comma (,) within a sentence, it is treated as an intentional signal and Google has build into it's search engine some value that you can control. The pipe character is not the only character that Google treats as special, the colon character is (:) another with it's own sets of behaviors.
Specifically, your question refers to how Google treats the last segment using a pipe character for branding. In your case, nothing will change. Here is why.
Google is specifically looking for a brand in the last section. If your brand is recognized as a brand within the brand ontology such as Kellogg, Mars, Coke Cola, etc., Google will primarily defer to the ontology. If your brand does not exist in the brand ontology (or even if it does), Google will specifically look at the terms within the brand and the domain name.
- example brand
Google will look for recognized terms using a variety of methods including n-gram and word boundaries. In my example, both example and brand would be recognized terms and used as very important signals for search. Google also compares what it sees to the domain name. All three examples would signal the domain name so that example brand or examplebrand would equal examplebrand.com. As a result, examplebrand could also be properly matched in search queries against example brand within the title. Potentially, a search for a brand eb could potentially return your brand depending upon the strength of the branding signals as compared to other sites.
As far as the options, all three would mostly work the same, however, much of the strength of how it would work would be dependent upon the terms used. If the terms are too generic, then the strength of the brand can be diluted by other sites. The more specific, the better. For example, craftsman tools. Both are generic terms, however the strength of the terms used as a signal would indicate the brand Craftsman Tools stronger than fresh flowers could. Part of this would be the brand ontology that would signal Craftsman Tools as a brand belonging to Sears. Another part would be that in the search query, fresh flowers has less of specific meaning than craftsman tools which would most often be an intentional search for the brand.
If your brand is not strong, I would recommend example brand contrary to what one would expect. It signals both search term match and the match against the domain name even if it does not appear to be needed. It would work well which ever you chose, however, weak branding signals would become convoluted regardless so why not be clear in how you want your site to be matched against a search query and not rely upon how Google processes things? Also, keep in mind that Bing and Yahoo! exists also.
As for using the pipe character, I recommend that you always put spaces around the pipe for readability. Google will ignore the spaces, however, I highly recommend that you stay traditional and include the spaces anyway.