This gorgeous piece has been included in the Typography Brilliance section of Typographysical Appearance 3 - a news article about text art. If you have time, please do take a look as it features a lot of resources. I hope it would be useful to you, too, and I'd appreciate it if you leave a comment. Thank you for sharing your brilliant work with us!
That definition sounds more like a "symbol" to me. I would have thought a memento was more like a synechdoche - a poetic device in which a single detail is used to represent an entire thing. That is, a memento is a small (usually physical) part of some experience that we keep to remind us of the whole thing.
I'm not arguing, of course. Please don't take any offense. The picture is neat, though I'm a bit puzzled by it. The typography is interesting. Did you purposefully arrange the letters so that it says
I didn't put to much attention on the meaning of the word "memento", this is a personal work and a "typography experiment" as i wrote in the comment, so i concentrate more on the typography and the composition.