Wreath - This is a decorative Laurel of roses or other garlands separating the crest and helmut.

Crest - The crest was an ornament atop the helmet.  While the size of this engraving makes fine detail and accuracy difficult, this is probably a bear.  The evidence is:  the general look, small ears, and the bear is the only animal that was depicted in heraldry with a muzzle.  Sometimes the crest had a particular meaning, most often it was a decorative object the designer or holder just admired.

Cadence Marks - These marks denote which generation this seal is designed for.  Each new generation and/or different son wouild add a "cadence mark" to the seal.  This seal has many half-moon cadence marks.  The very first use of the seal would have had none.

Helmet - This was a holdover decoration from the cursading knights and is used on virtually all seals.   The helmet style can help determine seals  time of origin.  This design is typeical of 15th century helmet design.

Shield - The oval shield was almost exclusively used by the clergy.  This is most appropriate for the Johnson seal as many generations were either clergy or closely associcated with the church.

Cross - The image of the cross on the shield is further evidence of the Johnson close association with religion.  This particular cross design is called "cross flory", reflecting the Norman (French) influence on early England.