When you drag onto an application on the Dock or an unopened folder in Finder, the operating system isn't sure if you just intend to drag-and-drop, or if you want to place the dragged item in a specific place once the folder or application is opened.
In an application like a web browser, where a window can have multiple tabs, the application doesn't know which tab you're trying to send the item to, or if you want to open a new tab with that item to view it, or ...
If you drag-and-hold over an application or unopened folder, after a few seconds the application or folder will open (or un-minimize). This is called spring-loaded folders. There's no way to disable this. In the case of folders, you can continue to open subfolders in this manner until you find the location you want.
In the case of some applications, you can change what happens with the dragged item.
In Chrome, for example, you can:
- drag onto the tab bar to open a new tab with that item for viewing
- drag onto the Bookmark Toolbar to create a bookmark to it
- drag into the address bar to open that item in the current tab
- drag onto a target in the loaded tab (such as your Imgur example)
- drag onto another tab in the tab bar to bring that tab to the front, and then into the address bar or a target location on the page loaded in that tab
To answer your direct question: Having the application window or folder open somewhere on your desktop (even if it's on a different monitor that's hooked up to your computer) will allow you to drag directly into the open application window and drop it immediately without delay.
Similarly if, somewhere on the screen, you can see the icon of a closed folder that you want to drag an item into, you can let go as soon as your mouse cursor is over the closed folder and it will drop the item into that folder without delay or opening it.