Sharp leather tools are a dream to use and do a great job. From what I see you may have a dull one but there are somethings you need to know. Wet helps....not soaking but a brush with a damp sponge goes a long way. Also an edge trimmer is like a straight. Angle and pressure. It should cut smooth and you want to keep it at a 45 to the corner. As for the slicker same thing. Wet, angle and rub back and forth until your fingers go numb. Your actually burnishing the edge once shaped. Edge coat of some kind holds it all in place.
Your strop looks fine :<0)
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+1 on what pups says about sharp tools and edge trimmer. Good advice there.............