could you translate what's written under the monochrome image?

There is more than one monochromatic picture on the page, but I'll assume that it's the one you searched on. Another caveat, my Classical Greek is not that good, and my Modern Greek is almost non-existent aside from some pleasantries and food items. The page is in Modern Greek. One hint is in the caption under the image:

Η δηλητηρίαση του Αλέξανδρου σε μεσαιωνική παράσταση. Μπροστά διακρίνεται ο οινοχόος Ιόλλας που έριξε το δηλητήριο στο κρασί του

Μπροστά (Mprosta) 'before, ahead, in front'. The phonology of Modern Greek is quite different from Classical Greek. Think of the difference between Latin and Italian. {β} beta was pronounced /b/ in CGk, but is pronounced /v/ in MGk. {μπ} is a digraph for /b/ in MGk.

Anyway: The poisoning of Alexander in a Medieval representation. In front is Iollas (link), the cup-bearer, who threw the poison in.

Ceci n'est pas un seing.