if we miss any company logo it makes an high serrity 
acdording to client and low proroty to us

If we miss the Sign-in button on the login screen we
consider it has a severity and there is any colour changes
in home page we will consider it has a low prirority.

hardware defects comes under high severity defects.under 
this defect if analyse 
high proirity defect:-if build is not accepting any h/w 
device then it comes under high priority.
low priority defect:-if build is accepting h/w device but 
o/p is wrong from the device then it is considered as low 
priority defect.

one thing to remember is
severity:severity means seriousness of the defect with 
respect to functionality.
priority:priority means importance of the defect w.r.t to 
customer expectation.