1879 And 1880 Florin

the effigy in your pics is called "Gothic", and was only used on florins and a few other denominations, from 1849.
The Young Head was used on most other denominations from 1837.
In 1887, the year of Victoria's Golden Jubilee, the Jubilee Head was introduced.
This shows her wearing her newly-made Jubilee Crown.
Most denominations have two versions in 1887 - YH & JH.
The story goes that the Queen did not like her Jubilee portrait, and so that was discontinued after a relatively short time in service.
It was replaced in 1893 by the Old Head, sometimes called Veiled Head portrait, which remained in use for the remainder of her reign.
I don't know if 1893 used two portraits.

(I know it is an old thread but needs an answer)I think the question was specifically aimed at the two different types of 1880 dated florins which indeed has two different profiles but it is very hard to tell them apart The rare type 1880 obverse has a younger portrait A more aquiline nose ,rounder forehead, a more protuberant eye and the hair plat below the ear sits slightly lower. Also the reference to portraits used from 1868-1877 is what you are looking for . I did notice on those coins the cross pattee has 8 jewels in the center and the normal 1880 has only 6 jewels.(unconfirmed all years 1868-1877 had 8 jewels only) I hope if anything it is a little clearer as to what to look for