Do my veneers look too long? (Photos)

The final decision is yours of course!  They look nice but can easily by polished just a tad bit shorter if your preference BUT you cannot go back to longer, so just a little adjustment at a time is advisable.  

Hi:From the photos, the veneers appear correct length, shape and thickness.  However, a full face photo would also be helpful.  If you are very self councious of the length, it can easily be adjusted.Best,Dr. Maddahi

I hope that your veneers are the final stage of a process via which you were able to see how they would look either in your mouth (as a simulation) or a digital model before they were fitted?
These days either of those options is a minimum to prevent patients from regretting or reconsidering their final decisions on aspects such as length and proportion and also shade of their veneers. 
If you have not, speak to your dentist and he / she may be able to simulate the changes you are considering now before you embark on irreversible changes to the veneers themselves. Time does at this stage help for you to see exactly what you do not like about them and what you would like to change. 
Good luck with however you decide to proceed. 
Kind regards

Thomas Dey, BDS, MSc 

It's difficult to determine if your veneers are too long without a full photo of your face. If you are happy with the length I wouldn't worry about it. If you are concerned return to the dentist and share your concerns.