When you are applying to an art show or gallery, submit a unified body of work. You need to show the jury that you have a vision, a voice as an artist. Scattered work in terms of styles/voice makes you look inexperienced. This doesn't mean you can't experiment with your work- it just means that for any particular show you should submit a body of work with a clear focus.
Also, when submitting images of several pieces, make sure the images look good together as a group. Sometimes jurors will view each image individually - other times they will view your entire submission at once - you just never know. Make sure that your images read well both individually and as a group.
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