First off, of course you can draw or sculpt the same person different ways.
Say you went to St. Gregory the Great Church. Father might have picked out a statue of St. Gregory enthroned as Pope, standing with a crook as a Pope and bishop and shepherd, as a monk, as an abbot, as a writer, as the organizer of Gregorian chant, or even as “the business manager for Rome’s poor.” He did a lot of different stuff and filled a lot of different roles.
Statues of Mary and Jesus not only reflect different styles and roles, but different Biblical titles, different historical visions and apparitions, different professions and statuses in life, or famous centers of Catholic worship. (Often in the US, this also tells you where people in a parish came from, or which religious orders have served there.)
Using the iconography for one title or another allows you to point the viewer to certain specific virtues or thoughts about a person. It doesn’t deny the rest of that person’s character or deeds, but it is a message.
So for example, a picture of Jesus and His Sacred Heart honors His Wounds that He suffered for our salvation (because His Heart was pierced when the soldier speared His Side), as well as His burning love and mercy for us. You might think of all sorts of Biblical verses about the word “heart.”
A statue of the Infant of Prague, on the other hand, emphasizes that Jesus was born among us as a little child, helpless; but that He also reigned both as God and as the Son of David, even as a tiny toddler. You might think of the vineyard owner who sent His son. You might think of “A child is born, a son is given.”
(In an old immigrant church, it also suggests that some people in the parish may have been born Czechs, Austrians, Hungarians, etc. It may also suggest a need in that parish for certain devotions associated with the Infant of Prague.)
And so on…
It’s natural to think this way, because Hebrew poetry was very big on parallelism and repetition of titles and descriptions of the Most High.
It also can help people psychologically. People who are suffering may find it easier to pray when thinking of Christ’s suffering. People who want patience with their kids may learn from praying with a picture in their mind of Baby Jesus. People who have trouble picturing stuff happening in ancient Israel can benefit from pictures of Biblical figures that look and dress like them. (And so, sometimes the picture or title you like best can tell you something about yourself and your faith life.)
The Church is very generous about allowing this kind of artistic and devotional latitude, even within the walls of one single church. That’s a feature, not a bug.
If the Stations of the Cross doesn’t bother you, when it’s 14 pictures of the same Jesus on the same Friday, I’d say that having two different statues of Mary or Jesus or the parish patron saint shouldn’t bother you a bit.
