I'm a graphologist and a clinician; I tend to get to know a little bit about people by peering at their handwriting. Looking at Barbara Streisand's signature, we do find the theme of duality. Barbra's first name (representing the private self) is scripted in one style of writing whereas her last name (representing her professional self) is scripted in a completely different style of writing.
Note how she loyally reproduces the copybook script she learned in school and, in so doing, shows us that, first and foremost, she values fitting in. Such writers, amiable and good-natured, easily lapse into people-pleasing. And they often harbor secret self-negating habits designed to help them keep insecurities at bay.
The field of graphology, or handwriting analysis, asserts that handwriting, in general, and signatures, specifically, relay information about the identity of the writer. The signature -- chosen as the writer's representative on the page -- often embeds symbols that may tell us about the writer's identifications. Here's what Osama Bin Laden's signature says about his terrible ways.
Take a look at Trump's signature. In general, cursive handwriting is comprised of straight lines and loops. But Trump favours straight lines and does away with curves or loops. For the graphologist, roundedness implies emotionality and softer aspects of the personality. But what is the meaning of the straight line?