Dean, you have a nice command of the trombone. Intonation, tone, high range, clean articulation is all very nice! You've done good work to get to your level of proficiency with the horn. Bravo.

You wrote that you need a little more emotion, and you are right. When you listen to yourself, can you hear WHY it lacks the emotion you wish for? Part of the answer is that most of your improvisation consists of scales. Maybe not root to root scales, but hear the predominant intervals between most of your notes. They are half steps and whole steps: scale intervals.

I recorded myself playing over the tune as an example of the effect of playing wider intervals. I think it creates more interest. The listener doesn't know what is coming next, as apposed to the more predictable major and minor seconds up and down.

Next, consider the variety of note lengths in your solo. Most of yours were eighth and quarter notes. Variety adds emotion. We like surprise and are bored with the predictable. So, consider the variety of range, intervals, note lengths, harmonic tension and release that you can put into your solo. listen to great songs. They contain some of those same ingredients.

You have a lot of good stuff going on with your playing. I think a little spice could go a long way to taking you to the next level.