There is a fix for this. It is partly the plugin. The plugin has code for it, and is calling for the image ic_ok.png. Not all themes have this image included. The Simplicity theme has a ic_ok.svg image in the themes images folder, and has css to use that one to show the check mark when the gift is selected.

Here's one way to fix it.
1. Go to Oxwall / includes / and open the config.php
 a. at the bottom of the page; find "Dev Mode". Change this from false to true, and click save.
2. Go to ow_themes / simplicity / images, and copy the ic_ok.svg image to your theme's images folder.
3. Go to ow_plugins / virtual gifts / views / components, and open send_gifts.htm
 a. on line 15 change top from 8px to 0px.
 b. on line 16 change left from 8px to 0px.
 c. on line 19 change ic_ok.png to ic_ok.svg
 d. click save.
4. Go to your site, and refresh the page. This will load your changes.
5. Go back to the config.php file, and change Dev Mode back to False, and click save.

Note. Once the plugin is corrected all you need to do is copy the ic_ok.svg image into any theme's images folder that doesn't have it.

This will revert back with any theme, or virtual gift plugin update. The theme dev can add their own image, and css to address this as well. I will be doing this in my themes.

Here's another solution that may be easier, if you aren't comfortable changing files.

Add this to the custom css for the theme in the admin panel. This will change the background color when the gift is selected.

With the theme active go to admin / appearance / customize, and open the css tab. You will see an empty box under the main css box. Click save after you add the following. You can change the color below to whatever you need to suit the theme.

.ow_gift_templates .ow_gift_checked {
    top: 0px !important;
    left: 0px !important;
    width: 100% !important;
    height: 100% !important;
    background-color: rgba(0,0,0,0.2);
}

Thank you so much.  I have not had time to try the first suggestion.  I am sure that will look a bit more professional.  I did your second suggestion and it worked perfectly.  I have been trying to figure this out for two weeks.  I really do appreciate your help.

Glad it worked. I'm glad I seen this post. My themes didn't have the image either. I added a Fontawesome solution on my themes. The way the plugin is set up is that when you click the gift; it places a check mark in the top left corner. Mine will now show the check mark.