It is not forbidden at all. If you've got a picture of a tool or component or whatever, it's likely to have the brand on it somewhere. If you bought a particular item for your project, and it's important (or useful) that that exact item be used for the project to work, then you should say so. However, if you're just bringing in all of your own products as a form of sneaky advertising, we call that "spam." The users who see it will flag your I'ble (or forum topic), and it is likely to be remove. This also violates the Terms of Service agreement and your account may be subject to termination.