One of the first things that you will notice in an Eastern Catholic Church when you walk in is all the icons. What is an Icon? Well I hope to shed some light on this. The best definition of the Orthodox (Catholic) definition of Icons if from the Greek Orthodox Archdiocese of America.
Icon: the Orthodox Definition
Icon of our Savior Jesus Christ- Holy Resurrection Monastery
The Orthodox stressed the role played by the icon in our salvation. Man was created in the image of God (Gen. 1:26, 27) but allowed that image, and with it the world, to be corrupted. God assumed a fully human nature without ceasing to be fully God and thereby restored the image – not just ethically, through His teachings, but in His whole person, as is proven by His bodily resurrection. An icon of Christ affirms the reality of that reconciliation of the human and the divine and enables us to contemplate the person who is the model for our theosis.
The controversy resulted in the sharpening of certain other ideas. The image is equivalent to Scripture as a revelation of the truth. The image bears witness to the sanctification of the matter by the Incarnation. A valid image is one that is faithful to its prototype.
This last point is illustrated by the history of Byzantine art. Fidelity to a sacred prototype means fidelity to a transfigured reality, and this fact rules out “photographic” realism, which would merely reproduce the likeness of the world in a state of corruption. Only in the ascetic and liturgical life of the Church is the world transfigured, and only in the iconographic tradition of the Church can one find the visual formulas appropriate to that higher reality. It is not necessary that an image duplicate precisely the colors, shapes, and composition of an accepted formula; but whatever changes are made must conform to, and confirm, the true meaning of the subject, and this presupposes an artist who is immersed in the life of the Church. An image changed to suit an individual’s taste is as dangerous as a doctored Scriptural text.
Tradition atributes the first Icon to be painted by Saint Luke. In the western Church the use of sacred art is common in the form of statues but there has been a recent revival of Icons in the Roman Church. Icons were defended as a doctrine of the Faith at the Seventh Ecumenical Council and one can’t go into a Eastern Catholic (or Orthodox) Church without seeing Icons all over the Church.

Coptic Icon- Holy Resurrection Monastery
Eastern Altars are enclosed by a screen of Icons. Homes of Eastern Christians traditionally have a corner in it with the Icons of the families patron saints. My Icon corner is in my room and has many Icons of our Lord, The Holy Theotokos and various Saints of God.
We must always remember Icons are to be venerated and not worshiped- Worship is for God alone! Icons give us a glimpse into the spiritual reality of the person or event it is portraying.

One of my favorite stories around the history of Holy Icons is the tradition passed down that St Luke painted an image of Jesus’s mother on a board from the family table.
Have you visited the website http://www.IconsExplained.com? This is a global site with a wealth of information and imagery. Enjoy!