I would focus soley on the "adding a bit of size" part of your original plan. Obviously posting a lean side tricep shot makes you look good (we had that Ryu guy do the same thing a couple of months back, BUT, his not-posing as hard as he can pics gave a very different picture of his physique).
You're still fairly young, and while I"m going out on a limb here, I see most younger guys too focused on being lean and never really get the building muscle part down. I'm NOT advocating becoming a fat-ass and deluding yourself into thinking it's all muscle and you have to do it this way, BUT, most competitors I know get 15, 20, even 30 lbs above their contest weight during their off season. The first reason for this, is that their stage weight is MUCH LOWER than simply being lean in your bathroom mirror. If you're 142 lbs above, what are you looking to weigh onstage, 120 lbs at 5'5? It's not really a very smart plan IMO.
When I was first contemplating competing, I found others who were my height and similar structures and compared their pictures and offseason/stage weights with what I thought I was realistically capable of Rob Stein (guy on this very forum) is 5'5, and did his first contest this past year. Take a look at his pics (not just the zoomed in flexing selfie pics, but actual bodybuilding poses) and see how you stack up.