
These patterns are called Style & Motif and refer to how the ELEMENTs and STONEs (singly or in CLUSTERS) come together to form the general image and subparts of that image to create the whole.
The first thing you notice is the relation between the horizontal and vertical dimensions. The optic system is a targeting system, that is, it locates things it sees in a three-dimensional reference system left to right, up and down and front to back. For objects larger than a visual point (what physiological and sensory psychologists call "complex" and hyper-complex" "fields") this means shape. By the time you get to know about tiaras, that system is already pretty much programmed so that tiara shapes can be graded (and often judged) on the vertical-horizontal scale with a horizontal span of about twice the height being considered the best. If it is sigificantly flatter, like Celtic style tiaras, it is said to be PLATIC and if it is significantly sharper it is said to be LEPTIC.
STYLE: Style is a general category into which a design fits best. it can be named for a group of people like Celtic, a time period like Rennaissance or by something it looks like such as Butterfly, which is defined by having not a central APEX but where the tallest parts are two high points usually about 2/3 to 3/4 of the way in from the outermost points of their respective sides. in the manner of a butterfly wiht its wings outspread, Crown or Coronet; defined by the ELEMENT GROUPs being a series of VERTICES at the outsie, Antenna where the outermost ELEMENTS are a series of RAYs, sometimes with stones or clusters at the free end. Cloud tiaras are defined by having two or more TIERs of BILLOWED ELEMENTs . My Lynestrais a Cloud tiara with a central leaf. Art Deco ??? but I know it when I see it; it was often used for the "Millenium" tiaras and is used for Sci-Fi/Fantasy. Style, becuase it is hard to "put your finger on" in the case of individal tiaras, is an over-arching classification and different styles can and do overlap.
MOTIF: This is a recurring theme or shape expressed either by recurring CLLUSTERS, ELEMNET GROUPS or SELF ELEMETNS. The modern classic 5-heart tiara, usually a bridal, has a Heart motif, the oft-senn Audrey Hepburn tiara is a Floral motif and I have seen several Star motif tiaras. Purely abstract design tiaras still have a motif but it is the case that they are not in the form of a named shape type.
So simple: Right? Do not believe that for a moment. Styles may overlap or a tiara may be a composite style. Motifs may be composites, the focal or usially center point of a tiara may and usually does have a CLUSTER or SELF ELEMENT that is not repeated elsewhere. STYLE and MOTIF can often be associated. The greater number of Celtic tiaras have Floral MOTIFs and the FLORAL motif usually makes the tiara one of Celtic STYLE as in the case of the Audrey Hepburn tiara. If you choose to follow up on this, you will spend 10% of the time and efort learing the terminology, 10% learing to visualize it and the remaining 80% learning to spot it in real life.