Generally, if you can help it, you should endeavour to take away elements of distraction from photos of drama performances. The biggest problem with shooting drama performances is that there is often evidence of the backdrop(in your case a black cloth at the rear) unless the photographer is careful to avoid it. In some situations, you will need to get a tight shot of the performer to isolate an expression, rather than taking a full body shot which shows nothing at all.
Was your focus here her sniffing the flower? Her sitting on the table? Her in the scene? Try to have a particular focus when you make your images, and then bring that out succinctly, clearly, and powerfully. If for example you wanted to focus on her expression when sniffing the flower, a tight headshot would be in order and the 24-70 is the wrong lens to use, unless you can get close to the subject.
Next, notice how many elements that do not contribute are present in the picture. What value does the creased backdrop add? Or the chair? or the paper cup and litter in the background? Could you have avoided any of these? If you could then you should have. If you could only have avoided some, then avoid those and minimise the prominence of what you cannot exclude totally. Know the space well beforehand, it will help you to find better angles to produce more outstanding images.
On a side note, whoever was your school's lighting technician ought to be shot, the lighting is terrible.