Your image link is broken, so it's hard to guess why you'd need to use an image. If you're trying to time text on screen, you could try Resolve's captioning tools, which provide basic controls over appearance.
But if you absolutely need to use an image as your source, you can stack the image layer above your video on the timeline, then mask it however you need to using power windows in the color page. In order for the masking to take effect though, be sure to wire your last node to an alpha output. Do this by right-clicking anywhere in the background of the node editor and selecting "add alpha output." Then drag a noodle from the last blue square in the node tree to the new blue circle. Any power window's you've created (as long as their alphas are piped correctly) will now punch through and act as a mask to punch through your image. Keyframing is possible, though rudimentary, IMHO.
There are also titling tools built into Resolve, which provide more control over appearance than the captioning tools. These won't help you mask an image, however.
And last but not least, if you need complete control, there's Fusion. I would recommend the forum https://www.steakunderwater.com/wesuckless/index.php for help on this topic. There are a few discussions over there about driving this type of action automatically, with external .txt or .csv files, though you could certainly "hardwire" it more easily.