With all of the hard work that is put into answering relevant questions; would it be possible to reward users with upvotes for placing a second picture of their project to show what it looks like when they complete the task?
If I understand correctly, you want to reward an answer more than an upvote/acceptance? If it is, then you can put a bounty on the question after it has been posted for 2 days, then select "reward an existing answer" for the reason.
By putting a bounty, you basically "pay" the bounty using your reputation, meaning that your reputation will be reduced by the same amount for the bounty.
The bountied question will also be put on the "featured" tab for as long as 7 days, the maximum duration of a bounty.
After putting a bounty, you can then award the bounty after 24 hours, or wait until the maximum duration.
For more information, What is a bounty? How can I start one?