Léal Souvenir is written prominently on a false frame, false in that the artist had painted it on himself. He did this in many artworks and saw a frame as an extension of the original artwork, rather than simply a presentation tool. The lettering of Léal Souvenir translates as Loyal Remembrance and Van Eyck would often produce depictions that at first glance appeared to be sculptures of stone, before one takes a closer look. It is the boldest of lettering on this frame, but there are other elements of Latin more subtly added above and below it.
Beyond the standard painted frame and latin lettering, there is also the typical use of lighting in this portrait as found elsewhere in Van Eyck's career. Whilst he displays more of the subject's torso than normal, the background is dark and bland just as you would expect. The hands often are included in order to add symbolic items that would explain more about the subject, normally their occupation. The subject also has a fairly serious expression on his face which is seen in most Renaissance portraits. Some art historians have actually suggested that this is an expression of mourning, but it is hard to confirm that either way.
Having passed away relatively young, by today's standards, Van Eyck's career was significantly stunted in terms of output which makes each and every one of his surviving paintings all the more important. Furthermore, there are also only a handful of drawings around today too. This is an artist whose reputation is most certainly built on quality over quantity, something that can be found in several artists from this period due to the shorter lifespans that occurred during this time.
Portrait of a Young Man (Tymotheos) is now under the ownership of the National Gallery in London that itself has one of the finest collection of Renaissance and Baroque art in the world, alongside many paintings from more recent art movements too. You will find one of the sunflowers series from Vincent van Gogh, for example, as well as paintings by more traditional artists like Turner, Velazquez, Holbein and El Greco.