Action Details
Requirements and how-to articles for Tumblr's action:

Requirements
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Animated GIF Image
File format: .gif
Maximum file size: 3MB
Maximum width: 540 pixels
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How-To Articles
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0
Tumblr Help Center - Photo Posts
When you are logged in to Tumblr, navigate to the homepage (a.k.a. the "Dashboard") and at the top of the page next to your blog's avatar you should see a list of different types of media. Click "photo" and then choose whether you wish to upload a photo or use which has already been uploaded elsewhere.
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